v0.31.0: 3 new synths, 38 instrument presets

- Karplus-Strong pluck (physical modeling for guitar/harp/koto)
- Hammond organ (additive drawbar synthesis)
- String ensemble (filtered saw with body resonance formants)
- 38 instrument presets: score.part("lead", instrument="violin")
- Demo updated with pluck_synth, organ_synth, strings_synth

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -2,6 +2,51 @@
 
 All notable changes to PyTheory are documented here.
 
+## 0.31.0
+
+- 3 new synth engines: Karplus-Strong pluck, Hammond organ, string ensemble with body formants
+- 38 instrument presets: `score.part("lead", instrument="violin")`
+- Keys, strings, woodwinds, brass, plucked, synth, and mallet categories
+- 13 total synth waveforms
+
+## 0.30.0
+
+- Drums are a real Part — same effects pipeline as any voice
+- `score.drums("rock", split=True)` splits kit into kick/snare/hats/toms/cymbals/percussion Parts
+- Each split Part gets independent effects (reverb on snare, LP on hats, etc.)
+- `set_drum_effects()` applies to all drum Parts (split or not)
+- Sidechain triggers on kick only — hats and snare don't duck the pad
+- MIDI import via `Score.from_midi(path)`
+
+## 0.29.3
+
+- Drums are now a real Part — same effects pipeline as any other voice, zero code duplication
+- `score.parts["drums"]` is a standard Part with reverb, delay, lowpass, etc.
+- `set_drum_effects()` is sugar over the Part's attributes
+
+## 0.29.2
+
+- Add `score.set_drum_effects()` — reverb, delay, lowpass, distortion, chorus on the drum bus
+- Same effects engine as parts, zero code duplication
+
+## 0.29.1
+
+- Rename song.py → songs.py
+- Polish all 20 example songs with stereo, convolution reverb, humanize, detune, sidechain
+
+## 0.29.0
+
+- Add `Score.from_midi(path)` — import any Standard MIDI File into a Score
+- Minimal zero-dependency MIDI parser (Type 0 and Type 1)
+- Each channel becomes a named Part, channel 10 becomes drum hits
+- Tempo, time signature, velocities, and note durations preserved
+- Roundtrip: save_midi → from_midi works
+
+## 0.28.3
+
+- Rewrite `pytheory demo` — 8 moods with stereo, effects, humanize, convolution reverb, sidechain
+- Added Dub and Temple moods
+
 ## 0.28.2
 
 - Lower drum_humanize default to 0.15 — tighter, more professional feel

CLAUDE.md

@@ -0,0 +1,38 @@
+# Claude Code Instructions
+
+## Release Process
+
+When releasing to PyPI, always do all three:
+
+1. **Tag the commit**: `git tag v0.X.Y`
+2. **Push the tag**: `git push origin --tags`
+3. **Create a GitHub release**: `gh release create v0.X.Y --title "v0.X.Y: Short description" --notes "Release notes" --latest`
+
+Don't forget to update `CHANGELOG.md` *before* the release commit.
+
+## Version Bumping
+
+- `pyproject.toml` and `pytheory/__init__.py` must match
+- Run `uv lock` after changing the version
+- Patch releases (0.X.Y) for bug fixes and small additions
+- Minor releases (0.X.0) for new features
+
+## Testing
+
+```
+uv run python -m pytest test_pytheory.py -x -q --tb=short -m "not slow"
+```
+
+## Publishing
+
+```
+uv build && uv publish --token <token> dist/pytheory-0.X.Y*
+```
+
+## Music Preferences
+
+- Detune: keep at 8-15, don't go above 25
+- Humanize: 0.2 is the sweet spot for melodic parts
+- Drum humanize: 0.15 default is good
+- No swing unless specifically asked
+- Sine and triangle are underrated — use them more

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Kenneth Reitz
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

docs/guide/drums.rst

@@ -29,6 +29,50 @@ Score:
 
 The default is 0.15 — just enough to feel alive without sounding loose.
 
+Drums Are Parts
+~~~~~~~~~~~~~~~~
+
+Drums are a real Part — the same as any melodic voice. You can set
+effects on them the same way:
+
+.. code-block:: python
+
+   score.drums("rock", repeats=4)
+   score.parts["drums"].reverb_mix = 0.2
+   score.parts["drums"].reverb_type = "plate"
+
+Or use the shorthand:
+
+.. code-block:: python
+
+   score.set_drum_effects(reverb=0.2, reverb_type="plate", lowpass=8000)
+
+Split Drums
+~~~~~~~~~~~
+
+For maximum control, split the kit into separate Parts — kick, snare,
+hats, toms, cymbals, and percussion — each with independent effects:
+
+.. code-block:: python
+
+   score.drums("rock", repeats=4, split=True)
+
+   # Now each group is its own Part
+   score.parts["snare"].reverb_mix = 0.3
+   score.parts["snare"].reverb_type = "plate"
+   score.parts["hats"].lowpass = 7000
+   score.parts["kick"]  # dry, no effects
+
+   # set_drum_effects still works — applies to all drum Parts
+   score.set_drum_effects(reverb=0.1)
+
+This is how real studios work — the snare gets its own reverb send,
+the hats get their own EQ, the kick stays dry and punchy. Now you
+can do the same thing in Python.
+
+Sidechain compression triggers on kick hits only — hi-hats and snares
+don't duck the pad.
+
 Every drum sound is stereo-panned like a real kit — kick and snare
 center, hi-hat right, crash left, toms spread across the field,
 percussion instruments placed naturally. Put on headphones and you'll

docs/guide/playback.rst

@@ -177,3 +177,33 @@ Optional synth, envelope, and gap parameters:
    play_progression(chords, t=2000, envelope=Envelope.PAD)
 
 That's the workflow: hear it, tweak it, hear it again. When it sounds right, export to WAV or MIDI and take it somewhere bigger.
+
+MIDI Import
+-----------
+
+Load any Standard MIDI File into a Score — then play it through
+PyTheory's synth engine with effects, or analyze the theory:
+
+.. code-block:: python
+
+   from pytheory import Score
+   from pytheory.play import play_score
+
+   score = Score.from_midi("song.mid")
+
+   # See what's inside
+   for name, part in score.parts.items():
+       print(f"{name}: {len(part.notes)} notes")
+
+   # Change the synth and add effects
+   score.parts["ch1"].synth = "saw"
+   score.parts["ch1"].reverb_mix = 0.3
+
+   play_score(score)
+
+Each MIDI channel becomes a named Part (``ch1``, ``ch2``, etc.).
+Channel 10 (drums) becomes drum hits. Tempo, time signature,
+note durations, and velocities are all preserved.
+
+Download any MIDI file from the internet, load it, play it through
+the synth engine with reverb and delay. That's the whole idea.

docs/guide/quickstart.rst

@@ -233,7 +233,7 @@ drum voices with stereo panning.
 mandolin family, violin family, banjo, harp, oud, sitar, erhu, and
 more) with chord fingering generation and scale diagrams.
 
-**Output** — stereo playback, WAV export, MIDI export.
+**Output** — stereo playback, WAV export, MIDI import/export.
 
 **Interface** — REPL with tab completion (``pytheory repl``), CLI with
 15 commands. ``pytheory demo``, ``pytheory key``, ``pytheory chord``,

docs/guide/synths.rst

@@ -341,6 +341,89 @@ Reverb is also stereo — the left and right channels get different
 early reflection patterns, so the reverb tail occupies real space
 in the stereo field rather than sitting dead center.
 
+Physical Modeling
+-----------------
+
+Three synths go beyond traditional waveform synthesis into physical
+modeling territory — they simulate how real instruments produce sound.
+
+Karplus-Strong Pluck
+~~~~~~~~~~~~~~~~~~~~
+
+A burst of noise fed into a short delay line. The delay length sets
+the pitch, the feedback filter models the string decaying. This is
+how every physical modeling synth since 1983 does plucked strings.
+It sounds genuinely like a real guitar, harp, or koto.
+
+.. code-block:: python
+
+   guitar = score.part("guitar", synth="pluck_synth")
+   harp = score.part("harp", instrument="harp")  # uses pluck_synth
+
+Hammond Organ
+~~~~~~~~~~~~~
+
+Additive synthesis with drawbar harmonics — sine waves at the
+fundamental plus 2nd, 3rd, 4th, 5th, 6th, and 8th harmonics mixed
+at musical levels. Warm, round, unmistakably organ.
+
+.. code-block:: python
+
+   organ = score.part("organ", synth="organ_synth")
+
+String Ensemble
+~~~~~~~~~~~~~~~
+
+Filtered sawtooth with body resonance formants at ~500 Hz and ~1500 Hz,
+modeling the way a violin or cello body shapes the sound. Warmer and
+more "wooden" than a raw saw wave.
+
+.. code-block:: python
+
+   violin = score.part("violin", synth="strings_synth")
+
+Instrument Presets
+------------------
+
+Instead of choosing synth + envelope + effects manually, use an
+instrument preset — 38 predefined combinations that approximate real
+instruments:
+
+.. code-block:: python
+
+   piano = score.part("piano", instrument="piano")
+   violin = score.part("violin", instrument="violin")
+   guitar = score.part("guitar", instrument="acoustic_guitar")
+   organ = score.part("organ", instrument="organ")
+   bass = score.part("bass", instrument="upright_bass")
+
+Available instruments:
+
+**Keys**: piano, electric_piano, organ, harpsichord, celesta, music_box
+
+**Strings**: violin, viola, cello, contrabass, string_ensemble
+
+**Woodwinds**: flute, clarinet, oboe, bassoon
+
+**Brass**: trumpet, trombone, french_horn, tuba, brass_ensemble
+
+**Plucked**: acoustic_guitar, electric_guitar, distorted_guitar,
+bass_guitar, upright_bass, harp, sitar, koto
+
+**Synth**: synth_lead, synth_pad, synth_bass, acid_bass, 808_bass
+
+**Percussion**: vibraphone, marimba, xylophone, glockenspiel, tubular_bells
+
+Explicit kwargs override preset defaults:
+
+.. code-block:: python
+
+   # Piano with extra reverb
+   piano = score.part("piano", instrument="piano", reverb=0.5)
+
+   # Violin panned left
+   violin = score.part("v", instrument="violin", pan=-0.4)
+
 Choosing Synth and Envelope Combos
 ----------------------------------
 

docs/index.rst

@@ -83,7 +83,7 @@ What's Inside
   lowpass (with resonance), distortion, chorus, sidechain compression,
   automation, LFOs. Master bus compressor/limiter
 - **Instruments** — 25 presets with fingering generation
-- **Output** — stereo playback, WAV, MIDI export
+- **Output** — stereo playback, WAV export, MIDI import/export
 - **Interface** — REPL with tab completion, CLI (15 commands), ``pytheory demo``
 - **AI-friendly** — Claude Code can compose
   and play music through PyTheory from natural language

examples/songs.py

@@ -46,12 +46,17 @@ def bossa_nova_girl():
     score.drums("bossa nova", repeats=4)
 
     rhodes = score.part("rhodes", synth="fm", envelope="piano",
-                        volume=0.3, reverb=0.4, reverb_decay=1.8)
+                        volume=0.3, pan=-0.3,
+                        reverb=0.4, reverb_decay=1.8, reverb_type="plate",
+                        detune=8, humanize=0.2)
     lead = score.part("lead", synth="triangle", envelope="pluck",
-                      volume=0.45, delay=0.25, delay_time=0.32,
-                      delay_feedback=0.35, reverb=0.2)
+                      volume=0.45, pan=0.3,
+                      delay=0.25, delay_time=0.32, delay_feedback=0.35,
+                      reverb=0.2, reverb_type="plate",
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.45, lowpass=600)
+                      volume=0.45, pan=0.0, lowpass=600,
+                      humanize=0.15)
 
     for sym in ["Am", "Am", "Dm", "Dm", "E7", "E7", "Am", "Am"]:
         rhodes.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -86,11 +91,18 @@ def bebop_in_bb():
     score.drums("bebop", repeats=8, fill="jazz", fill_every=8)
 
     rhodes = score.part("rhodes", synth="fm", envelope="piano",
-                        volume=0.25, reverb=0.35, reverb_decay=1.2)
+                        volume=0.25, pan=-0.3,
+                        reverb=0.35, reverb_decay=1.2, reverb_type="plate",
+                        detune=8, humanize=0.2)
     lead = score.part("lead", synth="saw", envelope="pluck",
-                      volume=0.4, lowpass=4000, lowpass_q=1.1)
+                      volume=0.4, pan=0.25,
+                      lowpass=4000, lowpass_q=1.1,
+                      delay=0.15, delay_time=0.19, delay_feedback=0.25,
+                      reverb=0.15, reverb_type="plate",
+                      humanize=0.2)
     bass = score.part("bass", synth="triangle", envelope="pluck",
-                      volume=0.4, lowpass=900)
+                      volume=0.4, pan=0.0, lowpass=500,
+                      humanize=0.15)
 
     for sym in ["Bb", "Gm", "Cm", "F7"] * 2:
         rhodes.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -133,12 +145,17 @@ def salsa_descarga():
     score.drums("salsa", repeats=8, fill="salsa", fill_every=4)
 
     pads = score.part("pads", synth="pwm_slow", envelope="pad",
-                      volume=0.2, reverb=0.3, lowpass=2000)
+                      volume=0.2, pan=-0.35,
+                      reverb=0.3, reverb_type="plate", lowpass=2000,
+                      detune=10, humanize=0.2)
     lead = score.part("lead", synth="saw", envelope="pluck",
-                      volume=0.4, delay=0.2, delay_time=0.167,
-                      delay_feedback=0.3)
+                      volume=0.4, pan=0.3,
+                      delay=0.2, delay_time=0.167, delay_feedback=0.3,
+                      reverb=0.15, reverb_type="plate",
+                      humanize=0.2)
     bass = score.part("bass", synth="pulse", envelope="pluck",
-                      volume=0.45, lowpass=500, lowpass_q=1.3)
+                      volume=0.45, pan=0.0, lowpass=500, lowpass_q=1.3,
+                      humanize=0.15)
 
     for sym in ["Em7b5", "A7", "Dm7", "Bbmaj7"] * 2:
         pads.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -175,12 +192,19 @@ def afrobeat_groove():
     score.drums("afrobeat", repeats=8, fill="afrobeat", fill_every=8)
 
     pads = score.part("pads", synth="supersaw", envelope="pad",
-                      volume=0.2, reverb=0.4, reverb_decay=2.0,
-                      lowpass=3000)
+                      volume=0.2, pan=-0.3,
+                      reverb=0.4, reverb_decay=2.0, reverb_type="cathedral",
+                      lowpass=3000, detune=10, spread=0.6,
+                      humanize=0.2)
     lead = score.part("lead", synth="saw", envelope="pluck",
-                      volume=0.4, lowpass=3000, lowpass_q=1.0)
+                      volume=0.4, pan=0.3,
+                      lowpass=3000, lowpass_q=1.0,
+                      delay=0.2, delay_time=0.26, delay_feedback=0.3,
+                      reverb=0.15, reverb_type="plate",
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.5, lowpass=500)
+                      volume=0.5, pan=0.0, lowpass=500,
+                      humanize=0.15)
 
     for sym in ["Em", "Am", "D", "C"] * 2:
         pads.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -213,13 +237,18 @@ def reggae_one_drop():
     score.drums("reggae", repeats=8, fill="reggae", fill_every=8)
 
     chords = score.part("chords", synth="square", envelope="staccato",
-                        volume=0.2, reverb=0.5, reverb_decay=2.0,
-                        lowpass=2000)
+                        volume=0.2, pan=-0.4,
+                        reverb=0.5, reverb_decay=2.0, reverb_type="cathedral",
+                        lowpass=2000, detune=8,
+                        humanize=0.2)
     lead = score.part("lead", synth="triangle", envelope="strings",
-                      volume=0.4, delay=0.35, delay_time=0.5625,
-                      delay_feedback=0.45, reverb=0.3)
+                      volume=0.4, pan=0.3,
+                      delay=0.35, delay_time=0.5625, delay_feedback=0.45,
+                      reverb=0.3, reverb_type="cathedral",
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.55, lowpass=400, lowpass_q=1.3)
+                      volume=0.55, pan=0.0, lowpass=400, lowpass_q=1.3,
+                      humanize=0.15)
 
     for sym in ["G", "C", "D", "C"] * 2:
         chords.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -254,12 +283,18 @@ def funk_workout():
     score.drums("funk", repeats=8, fill="funk", fill_every=4)
 
     chords = score.part("chords", synth="square", envelope="staccato",
-                        volume=0.25, lowpass=2500, reverb=0.15)
+                        volume=0.25, pan=-0.4,
+                        lowpass=2500, reverb=0.15, reverb_type="plate",
+                        sidechain=0.4, humanize=0.2)
     lead = score.part("lead", synth="saw", envelope="pluck",
-                      volume=0.4, lowpass=3500, lowpass_q=1.5,
-                      delay=0.15, delay_time=0.15, delay_feedback=0.25)
+                      volume=0.4, pan=0.35,
+                      lowpass=3500, lowpass_q=1.5,
+                      delay=0.15, delay_time=0.15, delay_feedback=0.25,
+                      reverb=0.1, reverb_type="plate",
+                      humanize=0.2)
     bass = score.part("bass", synth="pulse", envelope="pluck",
-                      volume=0.5, lowpass=600, lowpass_q=1.2)
+                      volume=0.5, pan=0.0, lowpass=600, lowpass_q=1.2,
+                      humanize=0.15)
 
     for sym in ["Em", "Am", "D", "B7"] * 2:
         chords.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -298,13 +333,17 @@ def blues_shuffle():
     score.drums("12/8 blues", repeats=6)
 
     chords = score.part("chords", synth="fm", envelope="piano",
-                        volume=0.3, reverb=0.3, reverb_decay=1.5)
+                        volume=0.3, pan=-0.3,
+                        reverb=0.3, reverb_decay=1.5, reverb_type="plate",
+                        detune=8, humanize=0.2)
     lead = score.part("lead", synth="saw", envelope="pluck",
-                      volume=0.45, reverb=0.3, reverb_decay=1.2,
+                      volume=0.45, pan=0.25,
+                      reverb=0.3, reverb_decay=1.2, reverb_type="plate",
                       delay=0.2, delay_time=0.43, delay_feedback=0.3,
-                      lowpass=3500)
+                      lowpass=3500, humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.5, lowpass=500)
+                      volume=0.5, pan=0.0, lowpass=500,
+                      humanize=0.15)
 
     for sym in ["A", "A", "D", "D", "E7", "A"]:
         chords.add(Chord.from_symbol(sym), Duration.DOTTED_HALF)
@@ -343,13 +382,18 @@ def samba_de_janeiro():
     score.drums("samba", repeats=8, fill="samba", fill_every=8)
 
     pads = score.part("pads", synth="supersaw", envelope="pad",
-                      volume=0.2, reverb=0.45, reverb_decay=2.0,
-                      lowpass=4000)
+                      volume=0.2, pan=-0.3,
+                      reverb=0.45, reverb_decay=2.0, reverb_type="plate",
+                      lowpass=4000, detune=10, spread=0.5,
+                      humanize=0.2)
     lead = score.part("lead", synth="triangle", envelope="pluck",
-                      volume=0.45, delay=0.2, delay_time=0.176,
-                      delay_feedback=0.3)
+                      volume=0.45, pan=0.3,
+                      delay=0.2, delay_time=0.176, delay_feedback=0.3,
+                      reverb=0.15, reverb_type="plate",
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.45, lowpass=700)
+                      volume=0.45, pan=0.0, lowpass=500,
+                      humanize=0.15)
 
     for sym in ["G", "Em", "Am", "D7"] * 2:
         pads.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -383,12 +427,17 @@ def jazz_waltz():
     score.drums("waltz", repeats=16)
 
     rhodes = score.part("rhodes", synth="fm", envelope="piano",
-                        volume=0.3, reverb=0.4, reverb_decay=2.0)
+                        volume=0.3, pan=-0.3,
+                        reverb=0.4, reverb_decay=2.0, reverb_type="cathedral",
+                        detune=8, humanize=0.2)
     lead = score.part("lead", synth="triangle", envelope="strings",
-                      volume=0.4, reverb=0.3, reverb_decay=1.5,
-                      delay=0.2, delay_time=0.4, delay_feedback=0.3)
+                      volume=0.4, pan=0.25,
+                      reverb=0.3, reverb_decay=1.5, reverb_type="plate",
+                      delay=0.2, delay_time=0.4, delay_feedback=0.3,
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.4, lowpass=600)
+                      volume=0.4, pan=0.0, lowpass=500,
+                      humanize=0.15)
 
     for _ in range(2):
         for sym in ["Fmaj7", "Gm", "C7", "Fmaj7"]:
@@ -423,14 +472,19 @@ def house_anthem():
     score.drums("house", repeats=8, fill="house", fill_every=8)
 
     pads = score.part("pads", synth="supersaw", envelope="pad",
-                      volume=0.25, reverb=0.5, reverb_decay=2.5,
-                      lowpass=5000)
+                      volume=0.25, pan=-0.3,
+                      reverb=0.5, reverb_decay=2.5, reverb_type="cathedral",
+                      lowpass=5000, detune=12, spread=0.7,
+                      sidechain=0.6, humanize=0.2)
     lead = score.part("lead", synth="saw", envelope="staccato",
-                      volume=0.35, lowpass=2000, lowpass_q=2.0,
-                      delay=0.2, delay_time=0.242,
-                      delay_feedback=0.35)
+                      volume=0.35, pan=0.3,
+                      lowpass=2000, lowpass_q=2.0,
+                      delay=0.2, delay_time=0.242, delay_feedback=0.35,
+                      reverb=0.15, reverb_type="plate",
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.55, lowpass=300)
+                      volume=0.55, pan=0.0, lowpass=300,
+                      sidechain=0.5, humanize=0.15)
 
     for sym in ["Cm", "Ab", "Bb", "Cm"] * 2:
         pads.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -480,16 +534,22 @@ def dub_kingston():
     score.drums("dub", repeats=8)
 
     chords = score.part("chords", synth="square", envelope="staccato",
-                        volume=0.2, reverb=0.6, reverb_decay=2.5,
-                        lowpass=1500, lowpass_q=0.9)
+                        volume=0.2, pan=-0.4,
+                        reverb=0.6, reverb_decay=2.5, reverb_type="cathedral",
+                        lowpass=1500, lowpass_q=0.9, detune=8,
+                        humanize=0.2)
     lead = score.part("lead", synth="triangle", envelope="strings",
-                      volume=0.4, delay=0.45, delay_time=0.625,
-                      delay_feedback=0.5, reverb=0.35, reverb_decay=2.0)
+                      volume=0.4, pan=0.3,
+                      delay=0.45, delay_time=0.625, delay_feedback=0.5,
+                      reverb=0.35, reverb_decay=2.0, reverb_type="cathedral",
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.6, lowpass=400, lowpass_q=1.5)
+                      volume=0.6, pan=0.0, lowpass=400, lowpass_q=1.5,
+                      humanize=0.15)
     siren = score.part("siren", synth="pwm_slow", envelope="pad",
-                       volume=0.15, reverb=0.7, reverb_decay=3.0,
-                       lowpass=1200)
+                       volume=0.15, pan=0.5,
+                       reverb=0.7, reverb_decay=3.0, reverb_type="cathedral",
+                       lowpass=1200, detune=10)
 
     for sym in ["Am", "Am", "Dm", "Dm", "Am", "Am", "Em", "Am"]:
         chords.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -526,14 +586,19 @@ def techno_minimal():
     score.drums("techno", repeats=8, fill="house", fill_every=8)
 
     pad = score.part("pad", synth="supersaw", envelope="pad",
-                     volume=0.2, reverb=0.5, reverb_decay=3.0,
-                     lowpass=3000)
+                     volume=0.2, pan=-0.3,
+                     reverb=0.5, reverb_decay=3.0, reverb_type="cathedral",
+                     lowpass=3000, detune=12, spread=0.7,
+                     sidechain=0.6, humanize=0.2)
     lead = score.part("lead", synth="pwm_fast", envelope="staccato",
-                      volume=0.35, lowpass=1500, lowpass_q=3.0,
-                      delay=0.3, delay_time=0.231,
-                      delay_feedback=0.4)
+                      volume=0.35, pan=0.3,
+                      lowpass=1500, lowpass_q=3.0,
+                      delay=0.3, delay_time=0.231, delay_feedback=0.4,
+                      reverb=0.1, reverb_type="plate",
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.55, lowpass=250)
+                      volume=0.55, pan=0.0, lowpass=250,
+                      sidechain=0.5, humanize=0.15)
 
     for sym in ["Fm", "Db", "Eb", "Fm"] * 2:
         pad.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -560,12 +625,17 @@ def gospel_shuffle():
     score.drums("gospel", repeats=8, fill="buildup", fill_every=8)
 
     organ = score.part("organ", synth="fm", envelope="organ",
-                       volume=0.3, reverb=0.45, reverb_decay=2.0)
+                       volume=0.3, pan=-0.3,
+                       reverb=0.45, reverb_decay=2.0, reverb_type="cathedral",
+                       detune=8, humanize=0.2)
     lead = score.part("lead", synth="triangle", envelope="pluck",
-                      volume=0.4, delay=0.2, delay_time=0.278,
-                      delay_feedback=0.3, reverb=0.2)
+                      volume=0.4, pan=0.3,
+                      delay=0.2, delay_time=0.278, delay_feedback=0.3,
+                      reverb=0.2, reverb_type="plate",
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.45, lowpass=500)
+                      volume=0.45, pan=0.0, lowpass=500,
+                      humanize=0.15)
 
     for sym in ["C", "Am", "F", "G"] * 2:
         organ.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -618,18 +688,23 @@ def dub_delay_madness():
             score._drum_hits.append(_Hit(DrumSound.RIMSHOT, offset + 3.5, 60))
 
     chords = score.part("skank", synth="square", envelope="staccato",
-                        volume=0.15, reverb=0.7, reverb_decay=3.0,
-                        lowpass=1200)
+                        volume=0.15, pan=-0.4,
+                        reverb=0.7, reverb_decay=3.0, reverb_type="cathedral",
+                        lowpass=1200, detune=8, humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.6, lowpass=350, lowpass_q=1.5)
+                      volume=0.6, pan=0.0, lowpass=350, lowpass_q=1.5,
+                      humanize=0.15)
     siren = score.part("siren", synth="pwm_slow", envelope="pad",
-                       volume=0.12, reverb=0.8, reverb_decay=4.0,
+                       volume=0.12, pan=0.5,
+                       reverb=0.8, reverb_decay=4.0, reverb_type="cathedral",
                        delay=0.4, delay_time=0.88, delay_feedback=0.6,
-                       lowpass=900)
+                       lowpass=900, detune=10)
     # Melodica stabs — sparse, lots of delay
     melodica = score.part("melodica", synth="triangle", envelope="pluck",
-                          volume=0.35, delay=0.6, delay_time=0.66,
-                          delay_feedback=0.55, reverb=0.5, reverb_decay=2.5)
+                          volume=0.35, pan=0.3,
+                          delay=0.6, delay_time=0.66, delay_feedback=0.55,
+                          reverb=0.5, reverb_decay=2.5, reverb_type="cathedral",
+                          humanize=0.2)
 
     for sym in ["Em", "Em", "Am", "Am", "Em", "Em", "Bm", "Em"]:
         chords.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -667,13 +742,18 @@ def drum_and_bass():
     score.drums("drum and bass", repeats=8, fill="buildup", fill_every=8)
 
     pads = score.part("pads", synth="supersaw", envelope="pad",
-                      volume=0.25, reverb=0.5, reverb_decay=2.5,
-                      lowpass=4000)
+                      volume=0.25, pan=-0.3,
+                      reverb=0.5, reverb_decay=2.5, reverb_type="plate",
+                      lowpass=4000, detune=10, spread=0.6,
+                      humanize=0.2)
     lead = score.part("lead", synth="triangle", envelope="strings",
-                      volume=0.4, delay=0.3, delay_time=0.172,
-                      delay_feedback=0.4, reverb=0.25)
+                      volume=0.4, pan=0.3,
+                      delay=0.3, delay_time=0.172, delay_feedback=0.4,
+                      reverb=0.25, reverb_type="plate",
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.55, lowpass=300)
+                      volume=0.55, pan=0.0, lowpass=300,
+                      humanize=0.15)
 
     for sym in ["Am", "F", "C", "G"] * 2:
         pads.add(Chord.from_symbol(sym), Duration.WHOLE)
@@ -708,18 +788,24 @@ def drake_vibes():
     score.drums("trap", repeats=8, fill="trap", fill_every=8)
 
     pads = score.part("pads", synth="supersaw", envelope="pad",
-                      volume=0.2, reverb=0.5, reverb_decay=3.0,
-                      lowpass=2500)
+                      volume=0.2, pan=-0.25,
+                      reverb=0.5, reverb_decay=3.0, reverb_type="cathedral",
+                      lowpass=2500, detune=12, spread=0.6,
+                      sidechain=0.4, humanize=0.2)
     bells = score.part("bells", synth="fm", envelope="bell",
-                       volume=0.3, reverb=0.4, reverb_decay=2.0,
-                       delay=0.25, delay_time=0.44,
-                       delay_feedback=0.35)
+                       volume=0.3, pan=0.4,
+                       reverb=0.4, reverb_decay=2.0, reverb_type="plate",
+                       delay=0.25, delay_time=0.44, delay_feedback=0.35,
+                       humanize=0.2)
     lead = score.part("lead", synth="pwm_slow", envelope="strings",
-                      volume=0.35, reverb=0.3, lowpass=2000,
-                      delay=0.2, delay_time=0.88, delay_feedback=0.3)
+                      volume=0.35, pan=-0.2,
+                      reverb=0.3, reverb_type="cathedral", lowpass=2000,
+                      delay=0.2, delay_time=0.88, delay_feedback=0.3,
+                      humanize=0.2)
     bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.6, lowpass=200, lowpass_q=1.8,
-                      distortion=0.4, distortion_drive=2.0)
+                      volume=0.6, pan=0.0, lowpass=200, lowpass_q=1.8,
+                      distortion=0.4, distortion_drive=2.0,
+                      sidechain=0.3, humanize=0.15)
 
     for sym in ["Ebm", "B", "Gb", "Db"] * 2:
         pads.add(Chord.from_symbol(sym), Duration.WHOLE)

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "pytheory"
-version = "0.28.2"
+version = "0.31.0"
 description = "Music Theory for Humans"
 readme = "README.md"
 license = "MIT"

pytheory/__init__.py

@@ -1,6 +1,6 @@
 """PyTheory: Music Theory for Humans."""
 
-__version__ = "0.28.2"
+__version__ = "0.31.0"
 
 from .tones import Tone, Interval
 from .systems import System, SYSTEMS
@@ -8,7 +8,7 @@ from .scales import TonedScale, Key, PROGRESSIONS
 from .chords import Chord, Fretboard, analyze_progression
 from .charts import CHARTS, Fingering, charts_for_fretboard
 
-from .rhythm import Duration, TimeSignature, Rest, Score, Part, Section, DrumSound, Pattern
+from .rhythm import Duration, TimeSignature, Rest, Score, Part, Section, DrumSound, Pattern, INSTRUMENTS
 from .rhythm import Note as RhythmNote  # rhythm.Note (tone + duration pairing)
 
 from .play import (play, save, save_midi, play_progression, play_pattern,
@@ -25,5 +25,5 @@ __all__ = [
     "play", "save", "save_midi", "play_progression", "play_pattern",
     "play_score", "Synth", "Envelope",
     "Duration", "TimeSignature", "RhythmNote", "Rest", "Score", "Part",
-    "DrumSound", "Pattern", "Section",
+    "DrumSound", "Pattern", "Section", "INSTRUMENTS",
 ]

pytheory/cli.py

@@ -228,75 +228,127 @@ def cmd_demo(args):
 
     moods = [
         {"name": "Bossa Nova", "key": ("A", "minor"), "drums": "bossa nova",
-         "bpm": 140, "prog": ("i", "iv", "V", "i"),
-         "lead_synth": "triangle", "pad_synth": "fm"},
+         "fill": "bossa nova", "bpm": 140,
+         "prog": ("i", "iv", "V", "i"),
+         "lead": ("pluck_synth", "none", 0.2, -0.1),
+         "pad": ("fm", "pad", -0.2),
+         "bass_lp": 600, "reverb_type": "plate"},
         {"name": "Jazz Club", "key": ("Bb", "major"), "drums": "jazz",
-         "bpm": 105, "prog": ("I", "vi", "ii", "V"),
-         "lead_synth": "saw", "pad_synth": "fm"},
-        {"name": "Afrobeat Groove", "key": ("E", "minor"), "drums": "afrobeat",
-         "bpm": 115, "prog": ("i", "iv", "V", "i"),
-         "lead_synth": "saw", "pad_synth": "supersaw"},
-        {"name": "House Pump", "key": ("C", "minor"), "drums": "house",
-         "bpm": 124, "prog": ("i", "IV", "V", "i"),
-         "lead_synth": "saw", "pad_synth": "supersaw"},
-        {"name": "Reggae One-Drop", "key": ("G", "major"), "drums": "reggae",
-         "bpm": 80, "prog": ("I", "IV", "V", "IV"),
-         "lead_synth": "triangle", "pad_synth": "pwm_slow"},
-        {"name": "Funk Workout", "key": ("E", "minor"), "drums": "funk",
-         "bpm": 100, "prog": ("i", "iv", "V", "i"),
-         "lead_synth": "saw", "pad_synth": "square"},
+         "fill": "jazz", "bpm": 108,
+         "prog": ("I", "vi", "ii", "V"),
+         "lead": ("triangle", "strings", 0.3, 0.2),
+         "pad": ("fm", "piano", -0.3),
+         "bass_lp": 700, "reverb_type": "plate"},
+        {"name": "Afrobeat", "key": ("E", "minor"), "drums": "afrobeat",
+         "fill": "afrobeat", "bpm": 115,
+         "prog": ("i", "iv", "V", "i"),
+         "lead": ("saw", "pluck", 0.15, 0.3),
+         "pad": ("supersaw", "pad", 0.0),
+         "bass_lp": 500, "reverb_type": "cathedral"},
+        {"name": "House", "key": ("C", "minor"), "drums": "house",
+         "fill": "house", "bpm": 124,
+         "prog": ("i", "IV", "V", "i"),
+         "lead": ("saw", "staccato", 0.2, 0.4),
+         "pad": ("supersaw", "pad", 0.0),
+         "bass_lp": 300, "reverb_type": "plate"},
+        {"name": "Reggae", "key": ("G", "major"), "drums": "reggae",
+         "fill": "reggae", "bpm": 80,
+         "prog": ("I", "IV", "V", "IV"),
+         "lead": ("pluck_synth", "none", 0.25, 0.15),
+         "pad": ("organ_synth", "organ", -0.3),
+         "bass_lp": 400, "reverb_type": "cathedral"},
+        {"name": "Funk", "key": ("E", "minor"), "drums": "funk",
+         "fill": "funk", "bpm": 100,
+         "prog": ("i", "iv", "V", "i"),
+         "lead": ("saw", "pluck", 0.15, 0.3),
+         "pad": ("square", "staccato", -0.4),
+         "bass_lp": 500, "reverb_type": "plate"},
+        {"name": "Dub", "key": ("A", "minor"), "drums": "dub",
+         "fill": "reggae", "bpm": 72,
+         "prog": ("i", "iv", "i", "V"),
+         "lead": ("triangle", "strings", 0.4, 0.2),
+         "pad": ("pwm_slow", "pad", -0.3),
+         "bass_lp": 350, "reverb_type": "cathedral"},
+        {"name": "Temple", "key": ("E", "minor"), "drums": "bolero",
+         "fill": "bossa nova", "bpm": 65,
+         "prog": ("i", "iv", "V", "i"),
+         "lead": ("pluck_synth", "none", 0.3, 0.2),
+         "pad": ("strings_synth", "pad", 0.0),
+         "bass_lp": 200, "reverb_type": "taj_mahal"},
     ]
 
     mood = random.choice(moods)
     tonic, mode = mood["key"]
     key = Key(tonic, mode)
     chords = key.progression(*mood["prog"])
+    lead_synth, lead_env, lead_reverb, lead_pan = mood["lead"]
+    pad_synth, pad_env, pad_pan = mood["pad"]
 
-    score = Score("4/4", bpm=mood["bpm"], swing=random.uniform(0.1, 0.4))
-    score.drums(mood["drums"], repeats=4, fill=random.choice(Pattern.list_fills()))
+    score = Score("4/4", bpm=mood["bpm"], drum_humanize=0.15)
+    score.drums(mood["drums"], repeats=4, fill=mood["fill"])
 
-    pad = score.part("pad", synth=mood["pad_synth"], envelope="pad",
-                     volume=0.25, reverb=0.4, reverb_decay=2.0,
-                     chorus=0.2)
-    lead = score.part("lead", synth=mood["lead_synth"], envelope="pluck",
-                      volume=0.4, delay=0.25, delay_time=0.375,
-                      delay_feedback=0.35, reverb=0.2,
-                      lowpass=3000, humanize=0.2)
-    bass = score.part("bass", synth="sine", envelope="pluck",
-                      volume=0.45, lowpass=500)
+    pad = score.part(
+        "pad", synth=pad_synth, envelope=pad_env,
+        volume=0.2, pan=pad_pan,
+        detune=10, spread=0.5,
+        reverb=0.4, reverb_type=mood["reverb_type"],
+        chorus=0.2,
+        sidechain=0.4 if mood["bpm"] > 100 else 0.0,
+    )
+    lead = score.part(
+        "lead", synth=lead_synth, envelope=lead_env,
+        volume=0.4, pan=lead_pan,
+        delay=0.2, delay_time=round(30 / mood["bpm"], 3),
+        delay_feedback=0.35,
+        reverb=lead_reverb, reverb_type=mood["reverb_type"],
+        lowpass=3500,
+        humanize=0.2,
+    )
+    bass = score.part(
+        "bass", synth="sine", envelope="pluck",
+        volume=0.45, pan=0.0,
+        lowpass=mood["bass_lp"],
+        humanize=0.15,
+    )
 
     for chord in chords * 2:
         pad.add(chord, Duration.WHOLE)
 
-    # Generate a melody from scale tones
+    # Melody: chord tones with passing tones, rests for breathing
     scale_tones = [t.name for t in key.scale.tones[:-1]]
-    for chord in chords:
+    for i, chord in enumerate(chords):
         chord_tones = [t.name for t in chord.tones]
-        for _ in range(4):
-            if random.random() < 0.2:
-                lead.rest(random.choice([0.5, 1.0]))
+        beats_left = 4.0
+        while beats_left > 0.5:
+            if random.random() < 0.25:
+                r = random.choice([0.5, 1.0, 1.5])
+                r = min(r, beats_left)
+                lead.rest(r)
+                beats_left -= r
             else:
-                n = random.choice(chord_tones if random.random() < 0.6 else scale_tones)
-                oct = random.choice([4, 5])
-                dur = random.choice([0.5, 0.67, 1.0])
-                lead.add(f"{n}{oct}", dur, velocity=random.randint(60, 120))
+                n = random.choice(chord_tones if random.random() < 0.65 else scale_tones)
+                oct = 5 if random.random() < 0.6 else 4
+                dur = random.choice([0.67, 1.0, 1.5, 2.0])
+                dur = min(dur, beats_left)
+                vel = random.randint(65, 105)
+                lead.add(f"{n}{oct}", dur, velocity=vel)
+                beats_left -= dur
 
-    root = chords[0].root
-    if root:
-        for chord in chords * 2:
-            r = chord.root
-            if r:
-                bass.add(f"{r.name}2", Duration.QUARTER, velocity=100)
-                bass.add(f"{r.name}2", Duration.QUARTER, velocity=60)
-                fifth = r.add(7)
-                bass.add(f"{fifth.name}2", Duration.QUARTER, velocity=70)
-                bass.add(f"{r.name}2", Duration.QUARTER, velocity=80)
+    # Bass: root-fifth with velocity accents
+    for chord in chords * 2:
+        r = chord.root
+        if r:
+            fifth = r.add(7)
+            bass.add(f"{r.name}2", Duration.QUARTER, velocity=95)
+            bass.add(f"{r.name}2", Duration.QUARTER, velocity=55)
+            bass.add(f"{fifth.name}2", Duration.QUARTER, velocity=65)
+            bass.add(f"{r.name}2", Duration.QUARTER, velocity=75)
 
     prog_str = " → ".join(c.symbol or str(c) for c in chords)
     print(f"  ♫  {mood['name']}")
     print(f"     {tonic} {mode} | {mood['bpm']} bpm")
     print(f"     {prog_str}")
-    print(f"     {mood['drums']} drums | {mood['lead_synth']} lead | {mood['pad_synth']} pad")
+    print(f"     {mood['drums']} | {lead_synth} lead | {pad_synth} pad | {mood['reverb_type']} reverb")
     print()
 
     play_score(score)

pytheory/play.py

@@ -190,6 +190,97 @@ def pwm_fast_wave(hz, peak=SAMPLE_PEAK, n_samples=SAMPLE_RATE):
     return pwm_wave(hz, peak, n_samples, lfo_rate=3.0)
 
 
+def pluck_wave(hz, peak=SAMPLE_PEAK, n_samples=SAMPLE_RATE):
+    """Karplus-Strong plucked string synthesis.
+
+    A burst of noise is fed into a short delay line with feedback —
+    the delay length determines the pitch, and the feedback filter
+    determines the decay. This is how every physical modeling synth
+    since 1983 does plucked strings. It sounds genuinely like a real
+    guitar, harp, or koto — not a synth approximation.
+
+    The algorithm: fill a buffer with random noise the length of one
+    period, then repeatedly average adjacent samples. The averaging
+    acts as a lowpass filter, gradually removing high harmonics —
+    exactly what a real vibrating string does as energy dissipates.
+    """
+    period = int(SAMPLE_RATE / hz)
+    if period < 2:
+        period = 2
+    # Initial noise burst — the "pluck"
+    buf = numpy.random.uniform(-1.0, 1.0, period).astype(numpy.float64)
+    out = numpy.zeros(n_samples, dtype=numpy.float64)
+    for i in range(n_samples):
+        out[i] = buf[i % period]
+        # Averaging filter: smooth adjacent samples (Karplus-Strong)
+        buf[i % period] = 0.5 * (buf[i % period] + buf[(i + 1) % period]) * 0.998
+    return (peak * out).astype(numpy.int16)
+
+
+def organ_wave(hz, peak=SAMPLE_PEAK, n_samples=SAMPLE_RATE):
+    """Hammond organ — additive synthesis with drawbar harmonics.
+
+    A real Hammond B3 has 9 drawbars that mix sine waves at different
+    harmonics. This models the classic "full" registration with all
+    drawbars pulled: fundamental, 2nd, 3rd, 4th, 5th, 6th, and 8th
+    harmonics at musical levels.
+
+    The result is warm, rich, and unmistakably organ — somewhere
+    between a sine wave and a square wave, with that characteristic
+    hollow roundness.
+    """
+    t = numpy.arange(n_samples, dtype=numpy.float64) / SAMPLE_RATE
+    # Drawbar levels (inspired by 888800000 — full even harmonics)
+    wave = (numpy.sin(2 * numpy.pi * hz * t) * 1.0 +           # 16' fundamental
+            numpy.sin(2 * numpy.pi * hz * 2 * t) * 0.8 +       # 8'
+            numpy.sin(2 * numpy.pi * hz * 3 * t) * 0.6 +       # 5 1/3'
+            numpy.sin(2 * numpy.pi * hz * 4 * t) * 0.5 +       # 4'
+            numpy.sin(2 * numpy.pi * hz * 5 * t) * 0.3 +       # 2 2/3'
+            numpy.sin(2 * numpy.pi * hz * 6 * t) * 0.25 +      # 2'
+            numpy.sin(2 * numpy.pi * hz * 8 * t) * 0.15)       # 1 3/5'
+    wave /= 3.5  # normalize
+    return (peak * wave).astype(numpy.int16)
+
+
+def strings_wave(hz, peak=SAMPLE_PEAK, n_samples=SAMPLE_RATE):
+    """String ensemble — filtered saw with body resonance formants.
+
+    Goes beyond raw sawtooth by modeling the resonant body of a
+    stringed instrument. Two formant peaks (at ~500 Hz and ~1500 Hz)
+    shape the spectrum the way a violin or cello body does — boosting
+    certain frequencies and cutting others.
+
+    The result is warmer and more "wooden" than a raw saw wave,
+    with the characteristic nasal quality of bowed strings.
+    """
+    # Base: sawtooth (all harmonics, like a bowed string)
+    length = SAMPLE_RATE / float(hz)
+    omega = numpy.pi * 2 / length
+    xvalues = numpy.arange(int(length)) * omega
+    onecycle = scipy.signal.sawtooth(xvalues, width=1)
+    wave = numpy.resize(onecycle, (n_samples,)).astype(numpy.float64)
+
+    # Body resonance formants — two bandpass peaks
+    # Formant 1: ~500 Hz (body resonance)
+    f1 = 500
+    bw1 = 200
+    b1, a1 = scipy.signal.butter(2, [max(20, f1 - bw1), f1 + bw1],
+                                  btype='band', fs=SAMPLE_RATE)
+    formant1 = scipy.signal.lfilter(b1, a1, wave)
+
+    # Formant 2: ~1500 Hz (bridge/top plate)
+    f2 = 1500
+    bw2 = 400
+    b2, a2 = scipy.signal.butter(2, [f2 - bw2, f2 + bw2],
+                                  btype='band', fs=SAMPLE_RATE)
+    formant2 = scipy.signal.lfilter(b2, a2, wave)
+
+    # Mix: original (attenuated) + formants
+    mixed = wave * 0.3 + formant1 * 0.4 + formant2 * 0.3
+
+    return (peak * mixed).astype(numpy.int16)
+
+
 def _apply_envelope(samples, attack, decay, sustain, release, sample_rate=SAMPLE_RATE):
     """Apply an ADSR amplitude envelope to a sample array.
 
@@ -291,6 +382,9 @@ class Synth(Enum):
     SUPERSAW = "supersaw"
     PWM_SLOW = "pwm_slow"
     PWM_FAST = "pwm_fast"
+    PLUCK = "pluck_synth"
+    ORGAN = "organ_synth"
+    STRINGS = "strings_synth"
 
     def __call__(self, hz, **kwargs):
         """Make Synth members callable — dispatches to the wave function."""
@@ -302,6 +396,8 @@ _SYNTH_FUNCTIONS = {
     "square": square_wave, "pulse": pulse_wave, "fm": fm_wave,
     "noise": noise_wave, "supersaw": supersaw_wave,
     "pwm_slow": pwm_slow_wave, "pwm_fast": pwm_fast_wave,
+    "pluck_synth": pluck_wave, "organ_synth": organ_wave,
+    "strings_synth": strings_wave,
 }
 
 
@@ -1836,6 +1932,8 @@ def render_score(score):
     # Named parts — each rendered to own buffer for per-part effects
     _pending_sidechain = []
     for part in score.parts.values():
+        if part.is_drums:
+            continue  # drums are rendered separately via _drum_hits
         if part.notes:
             part_buf = numpy.zeros(total_samples, dtype=numpy.float32)
             synth_fn = _resolve_synth(part.synth)
@@ -1950,44 +2048,57 @@ def render_score(score):
         DrumSound.MARACAS.value: 0.3,
     }
 
-    # Drum hits — render to mono sidechain trigger + stereo output
+    # Render all drum Parts (may be one "drums" or split into kick/snare/hats/etc.)
     import random as _drum_rnd
-    drum_buf = numpy.zeros(total_samples, dtype=numpy.float32)  # mono for sidechain
+    drum_buf = numpy.zeros(total_samples, dtype=numpy.float32)  # mono for sidechain (kick only)
     drum_stereo = numpy.zeros((total_samples, 2), dtype=numpy.float32)
     drum_swing = score.swing
-    drum_humanize = getattr(score, '_drum_humanize', 0.3)  # subtle by default
-    for hit in score._drum_hits:
-        pos = hit.position
-        if drum_swing > 0:
-            beat_frac = pos % 1.0
-            if 0.1 < beat_frac < 0.9:
-                pos += drum_swing * 0.15
-        if has_tempo_changes:
-            start = _beat_to_sample(pos, tempo_map)
-        else:
-            start = int(pos * samples_per_beat)
-        # Humanize: random timing jitter + velocity variation
-        if drum_humanize > 0:
-            max_offset = int(drum_humanize * 0.03 * samples_per_beat)
-            start += _drum_rnd.randint(-max_offset, max_offset)
-            start = max(0, start)
-        if start >= total_samples or start < 0:
-            continue
-        remaining = total_samples - start
-        hit_len = min(int(SAMPLE_RATE * 0.5), remaining)
-        wave = _render_drum_hit(hit.sound.value, hit_len)
-        vel = hit.velocity
-        if drum_humanize > 0:
-            vel_jitter = int(drum_humanize * 10)
-            vel = max(1, min(127, vel + _drum_rnd.randint(-vel_jitter, vel_jitter)))
-        vel_scale = vel / 127.0
-        mono_hit = wave * vel_scale * 0.7
-        # Mono sidechain trigger (always center)
-        drum_buf[start:start + hit_len] += mono_hit
-        # Stereo panned output
-        pan = _DRUM_PAN.get(hit.sound.value, 0.0)
-        panned = _pan_to_stereo(mono_hit, pan)
-        drum_stereo[start:start + hit_len] += panned
+    drum_humanize = getattr(score, '_drum_humanize', 0.15)
+
+    drum_parts = [p for p in score.parts.values() if p.is_drums]
+    for drum_part in drum_parts:
+        part_stereo = numpy.zeros((total_samples, 2), dtype=numpy.float32)
+        for hit in drum_part._drum_hits:
+            pos = hit.position
+            if drum_swing > 0:
+                beat_frac = pos % 1.0
+                if 0.1 < beat_frac < 0.9:
+                    pos += drum_swing * 0.15
+            if has_tempo_changes:
+                start = _beat_to_sample(pos, tempo_map)
+            else:
+                start = int(pos * samples_per_beat)
+            if drum_humanize > 0:
+                max_offset = int(drum_humanize * 0.03 * samples_per_beat)
+                start += _drum_rnd.randint(-max_offset, max_offset)
+                start = max(0, start)
+            if start >= total_samples or start < 0:
+                continue
+            remaining = total_samples - start
+            hit_len = min(int(SAMPLE_RATE * 0.5), remaining)
+            wave = _render_drum_hit(hit.sound.value, hit_len)
+            vel = hit.velocity
+            if drum_humanize > 0:
+                vel_jitter = int(drum_humanize * 10)
+                vel = max(1, min(127, vel + _drum_rnd.randint(-vel_jitter, vel_jitter)))
+            vel_scale = vel / 127.0
+            mono_hit = wave * vel_scale * 0.7
+            # Sidechain trigger — kick only
+            if hit.sound.value == DrumSound.KICK.value:
+                drum_buf[start:start + hit_len] += mono_hit
+            # Stereo panned output for this drum Part
+            pan = _DRUM_PAN.get(hit.sound.value, 0.0)
+            panned = _pan_to_stereo(mono_hit, pan)
+            part_stereo[start:start + hit_len] += panned
+
+        # Apply this drum Part's effects
+        has_drum_fx = (drum_part.lowpass > 0 or drum_part.delay_mix > 0
+                       or drum_part.reverb_mix > 0 or drum_part.distortion_mix > 0
+                       or drum_part.chorus_mix > 0)
+        if has_drum_fx:
+            for ch in range(2):
+                part_stereo[:, ch] = _apply_part_effects(part_stereo[:, ch], drum_part)
+        drum_stereo += part_stereo
 
     # Apply sidechain compression to parts that request it
     for part, part_buf in _pending_sidechain:
@@ -2001,7 +2112,7 @@ def render_score(score):
     if score.notes:
         stereo_buf += _pan_to_stereo(buf, 0.0)
 
-    # Drums: stereo panned
+    # Drums: stereo panned (with effects already applied)
     stereo_buf += drum_stereo
 
     # Master bus compressor/limiter (per channel)

pytheory/rhythm.py

@@ -7,6 +7,217 @@ from enum import Enum
 from typing import Optional
 
 
+# ── Instrument presets ────────────────────────────────────────────────────────
+# Predefined combinations of synth, envelope, effects, and parameters that
+# approximate real instruments.  Used by ``Score.part(instrument=...)``.
+
+INSTRUMENTS = {
+    # ── Keys ──
+    "piano": {
+        "synth": "fm", "envelope": "piano",
+        "detune": 5, "chorus": 0.1, "chorus_rate": 0.3,
+        "lowpass": 6000,
+    },
+    "electric_piano": {  # Rhodes/Wurlitzer
+        "synth": "fm", "envelope": "piano",
+        "detune": 6, "chorus": 0.2, "chorus_rate": 1.0,
+        "lowpass": 4000,
+    },
+    "organ": {
+        "synth": "organ_synth", "envelope": "organ",
+        "chorus": 0.2, "chorus_rate": 5.5,
+        "lowpass": 5000,
+    },
+    "harpsichord": {
+        "synth": "pluck_synth", "envelope": "none",
+        "lowpass": 3500,
+    },
+    "celesta": {
+        "synth": "fm", "envelope": "bell",
+        "lowpass": 8000,
+        "reverb": 0.3, "reverb_type": "plate",
+    },
+    "music_box": {
+        "synth": "sine", "envelope": "bell",
+        "lowpass": 6000,
+        "reverb": 0.25, "reverb_type": "plate",
+    },
+
+    # ── Strings ──
+    "violin": {
+        "synth": "strings_synth", "envelope": "strings",
+        "detune": 4, "lowpass": 5000,
+        "humanize": 0.15,
+    },
+    "viola": {
+        "synth": "strings_synth", "envelope": "strings",
+        "detune": 4, "lowpass": 3500,
+        "humanize": 0.15,
+    },
+    "cello": {
+        "synth": "strings_synth", "envelope": "strings",
+        "detune": 4, "lowpass": 2500,
+        "humanize": 0.15,
+    },
+    "contrabass": {
+        "synth": "strings_synth", "envelope": "strings",
+        "detune": 3, "lowpass": 1500,
+        "humanize": 0.1,
+    },
+    "string_ensemble": {
+        "synth": "strings_synth", "envelope": "pad",
+        "detune": 12, "spread": 0.6,
+        "chorus": 0.2, "chorus_rate": 0.5,
+        "lowpass": 4000,
+    },
+
+    # ── Woodwinds ──
+    "flute": {
+        "synth": "sine", "envelope": "strings",
+        "lowpass": 4000,
+        "humanize": 0.2,
+    },
+    "clarinet": {
+        "synth": "square", "envelope": "strings",
+        "lowpass": 3000,
+        "humanize": 0.15,
+    },
+    "oboe": {
+        "synth": "saw", "envelope": "strings",
+        "lowpass": 3500, "lowpass_q": 1.2,
+        "humanize": 0.15,
+    },
+    "bassoon": {
+        "synth": "saw", "envelope": "strings",
+        "lowpass": 2000,
+        "humanize": 0.15,
+    },
+
+    # ── Brass ──
+    "trumpet": {
+        "synth": "saw", "envelope": "pluck",
+        "detune": 3, "lowpass": 4000, "lowpass_q": 1.1,
+        "humanize": 0.15,
+    },
+    "trombone": {
+        "synth": "saw", "envelope": "strings",
+        "detune": 3, "lowpass": 2500,
+        "humanize": 0.15,
+    },
+    "french_horn": {
+        "synth": "saw", "envelope": "strings",
+        "detune": 4, "lowpass": 2000,
+        "chorus": 0.1,
+        "humanize": 0.15,
+    },
+    "tuba": {
+        "synth": "saw", "envelope": "strings",
+        "detune": 3, "lowpass": 1200,
+        "humanize": 0.1,
+    },
+    "brass_ensemble": {
+        "synth": "saw", "envelope": "strings",
+        "detune": 10, "spread": 0.4,
+        "lowpass": 3000,
+        "chorus": 0.15,
+    },
+
+    # ── Plucked ──
+    "acoustic_guitar": {
+        "synth": "pluck_synth", "envelope": "none",
+        "lowpass": 4000,
+        "humanize": 0.2,
+    },
+    "electric_guitar": {
+        "synth": "saw", "envelope": "pluck",
+        "detune": 5, "lowpass": 3500,
+        "humanize": 0.15,
+    },
+    "distorted_guitar": {
+        "synth": "saw", "envelope": "pluck",
+        "detune": 8, "distortion": 0.6, "distortion_drive": 5.0,
+        "lowpass": 3000,
+        "humanize": 0.15,
+    },
+    "bass_guitar": {
+        "synth": "triangle", "envelope": "pluck",
+        "lowpass": 1000,
+        "humanize": 0.1,
+    },
+    "upright_bass": {
+        "synth": "sine", "envelope": "pluck",
+        "lowpass": 800,
+        "humanize": 0.15,
+    },
+    "harp": {
+        "synth": "pluck_synth", "envelope": "none",
+        "lowpass": 5000,
+        "reverb": 0.3, "reverb_type": "plate",
+    },
+    "sitar": {
+        "synth": "saw", "envelope": "pluck",
+        "detune": 12, "lowpass": 3000, "lowpass_q": 1.5,
+        "humanize": 0.2,
+    },
+    "koto": {
+        "synth": "pluck_synth", "envelope": "none",
+        "lowpass": 4000,
+        "reverb": 0.2,
+    },
+
+    # ── Synth presets ──
+    "synth_lead": {
+        "synth": "saw", "envelope": "pluck",
+        "detune": 8, "lowpass": 3000,
+        "delay": 0.2, "delay_time": 0.25, "delay_feedback": 0.3,
+    },
+    "synth_pad": {
+        "synth": "supersaw", "envelope": "pad",
+        "detune": 12, "spread": 0.6,
+        "chorus": 0.2,
+    },
+    "synth_bass": {
+        "synth": "saw", "envelope": "pluck",
+        "lowpass": 800, "lowpass_q": 1.3,
+    },
+    "acid_bass": {
+        "synth": "saw", "envelope": "pad",
+        "legato": True, "glide": 0.03,
+        "distortion": 0.7, "distortion_drive": 8.0,
+        "lowpass": 800, "lowpass_q": 5.0,
+    },
+    "808_bass": {
+        "synth": "sine", "envelope": "pluck",
+        "distortion": 0.4, "distortion_drive": 2.5,
+        "lowpass": 200, "lowpass_q": 1.5,
+    },
+
+    # ── Percussion / Mallet ──
+    "vibraphone": {
+        "synth": "fm", "envelope": "bell",
+        "lowpass": 5000,
+        "reverb": 0.3, "reverb_type": "plate",
+    },
+    "marimba": {
+        "synth": "sine", "envelope": "pluck",
+        "lowpass": 3000,
+    },
+    "xylophone": {
+        "synth": "fm", "envelope": "pluck",
+        "lowpass": 6000,
+    },
+    "glockenspiel": {
+        "synth": "fm", "envelope": "bell",
+        "lowpass": 8000,
+        "reverb": 0.2,
+    },
+    "tubular_bells": {
+        "synth": "fm", "envelope": "bell",
+        "reverb": 0.4, "reverb_type": "cathedral",
+    },
+}
+
+
 class Duration(Enum):
     """Note durations in beats (quarter note = 1 beat)."""
 
@@ -1399,6 +1610,8 @@ class Part:
         self.pan = pan
         self.spread = spread
         self.notes: list[Note] = []
+        self._drum_hits: list[_Hit] = []
+        self._drum_pattern_beats: float = 0.0
         self._automation: list[tuple[float, dict]] = []  # (beat, {param: value})
 
     def add(self, tone_or_string, duration=Duration.QUARTER, *, velocity: int = 100) -> "Part":
@@ -1690,12 +1903,21 @@ class Part:
 
         return self
 
+    @property
+    def is_drums(self) -> bool:
+        """True if this part contains drum hits."""
+        return len(self._drum_hits) > 0
+
     @property
     def total_beats(self) -> float:
-        return sum(n.beats for n in self.notes)
+        note_beats = sum(n.beats for n in self.notes)
+        if self._drum_hits:
+            drum_beats = self._drum_pattern_beats
+            return max(note_beats, drum_beats)
+        return note_beats
 
     def __len__(self):
-        return len(self.notes)
+        return len(self.notes) + len(self._drum_hits)
 
     def __iter__(self):
         return iter(self.notes)
@@ -1786,34 +2008,94 @@ class Score:
         self._drum_humanize = drum_humanize
         self.notes: list[Note] = []
         self.parts: dict[str, Part] = {}
-        self._drum_hits: list[_Hit] = []
-        self._drum_pattern_beats: float = 0.0
         self._tempo_changes: list[tuple[float, int]] = []
         self._sections: dict[str, Section] = {}
         self._current_section: Optional[Section] = None
 
-    def part(self, name: str, *, synth: str = "sine",
-             envelope: str = "piano", volume: float = 0.5,
-             reverb: float = 0.0, reverb_decay: float = 1.0,
-             reverb_type: str = "algorithmic",
-             delay: float = 0.0, delay_time: float = 0.375,
-             delay_feedback: float = 0.4,
-             lowpass: float = 0.0, lowpass_q: float = 0.707,
-             distortion: float = 0.0, distortion_drive: float = 3.0,
-             legato: bool = False, glide: float = 0.0,
-             chorus: float = 0.0, chorus_rate: float = 1.5,
-             chorus_depth: float = 0.003,
+    def _ensure_drums_part(self) -> Part:
+        """Get or create the drums Part."""
+        if "drums" not in self.parts:
+            self.parts["drums"] = Part("drums", synth="sine", volume=0.7)
+        return self.parts["drums"]
+
+    @property
+    def _drum_hits(self) -> list:
+        """Proxy: drum hits live on the drums Part."""
+        return self._ensure_drums_part()._drum_hits
+
+    @property
+    def _drum_pattern_beats(self) -> float:
+        """Proxy: drum pattern beats live on the drums Part."""
+        return self._ensure_drums_part()._drum_pattern_beats
+
+    @_drum_pattern_beats.setter
+    def _drum_pattern_beats(self, value: float):
+        self._ensure_drums_part()._drum_pattern_beats = value
+
+    @property
+    def drum_effects(self) -> dict:
+        """Proxy: drum effects are just the drums Part's effect settings."""
+        p = self._ensure_drums_part()
+        return {
+            "reverb_mix": p.reverb_mix, "reverb_decay": p.reverb_decay,
+            "reverb_type": p.reverb_type,
+            "delay_mix": p.delay_mix, "delay_time": p.delay_time,
+            "delay_feedback": p.delay_feedback,
+            "lowpass": p.lowpass, "lowpass_q": p.lowpass_q,
+            "distortion_mix": p.distortion_mix,
+            "distortion_drive": p.distortion_drive,
+            "chorus_mix": p.chorus_mix,
+        }
+
+    def set_drum_effects(self, **kwargs) -> "Score":
+        """Set effects on all drum parts.
+
+        When drums are split, applies to every drum Part (kick, snare,
+        hats, etc.). When not split, applies to the single drums Part.
+
+        Example::
+
+            score.set_drum_effects(reverb=0.2, reverb_type="plate")
+        """
+        param_map = {"reverb": "reverb_mix", "delay": "delay_mix",
+                     "distortion": "distortion_mix", "chorus": "chorus_mix"}
+        drum_parts = [p for p in self.parts.values() if p.is_drums]
+        if not drum_parts:
+            drum_parts = [self._ensure_drums_part()]
+        for p in drum_parts:
+            for k, v in kwargs.items():
+                attr = param_map.get(k, k)
+                setattr(p, attr, v)
+        return self
+
+    def part(self, name: str, *, instrument: str = None,
+             synth: str = None, envelope: str = None,
+             volume: float = None,
+             reverb: float = None, reverb_decay: float = None,
+             reverb_type: str = None,
+             delay: float = None, delay_time: float = None,
+             delay_feedback: float = None,
+             lowpass: float = None, lowpass_q: float = None,
+             distortion: float = None, distortion_drive: float = None,
+             legato: bool = None, glide: float = None,
+             chorus: float = None, chorus_rate: float = None,
+             chorus_depth: float = None,
              swing: Optional[float] = None,
-             humanize: float = 0.0,
-             sidechain: float = 0.0,
-             sidechain_release: float = 0.1,
-             detune: float = 0.0,
-             pan: float = 0.0,
-             spread: float = 0.0) -> Part:
+             humanize: float = None,
+             sidechain: float = None,
+             sidechain_release: float = None,
+             detune: float = None,
+             pan: float = None,
+             spread: float = None) -> Part:
         """Create a named part with its own synth voice and effects.
 
         Args:
             name: Part name (e.g. ``"lead"``, ``"bass"``, ``"pads"``).
+            instrument: Instrument preset name (e.g. ``"piano"``,
+                ``"violin"``, ``"808_bass"``).  See :data:`INSTRUMENTS`
+                for the full list.  When set, the preset's synth, envelope,
+                and effects are used as defaults; any explicit keyword
+                argument still overrides the preset value.
             synth: Waveform — ``"sine"``, ``"saw"``, ``"triangle"``,
                 ``"square"``, ``"pulse"``, ``"fm"``, ``"noise"``,
                 ``"supersaw"``, ``"pwm_slow"``, ``"pwm_fast"``.
@@ -1861,23 +2143,72 @@ class Score:
 
             lead = score.part("lead", synth="saw", envelope="pluck",
                               reverb=0.3, delay=0.25, lowpass=3000)
+
+            # Or use an instrument preset:
+            piano = score.part("keys", instrument="piano")
         """
-        p = Part(name, synth=synth, envelope=envelope, volume=volume,
-                 reverb=reverb, reverb_decay=reverb_decay,
-                 reverb_type=reverb_type,
-                 delay=delay, delay_time=delay_time,
-                 delay_feedback=delay_feedback,
-                 lowpass=lowpass, lowpass_q=lowpass_q,
-                 distortion=distortion, distortion_drive=distortion_drive,
-                 legato=legato, glide=glide,
-                 chorus=chorus, chorus_rate=chorus_rate,
-                 chorus_depth=chorus_depth,
-                 swing=swing, humanize=humanize,
-                 sidechain=sidechain, sidechain_release=sidechain_release,
-                 detune=detune, pan=pan, spread=spread)
+        # Default values for all Part parameters.
+        _defaults = {
+            "synth": "sine", "envelope": "piano", "volume": 0.5,
+            "reverb": 0.0, "reverb_decay": 1.0, "reverb_type": "algorithmic",
+            "delay": 0.0, "delay_time": 0.375, "delay_feedback": 0.4,
+            "lowpass": 0.0, "lowpass_q": 0.707,
+            "distortion": 0.0, "distortion_drive": 3.0,
+            "legato": False, "glide": 0.0,
+            "chorus": 0.0, "chorus_rate": 1.5, "chorus_depth": 0.003,
+            "swing": None, "humanize": 0.0,
+            "sidechain": 0.0, "sidechain_release": 0.1,
+            "detune": 0.0, "pan": 0.0, "spread": 0.0,
+        }
+
+        # If an instrument preset is specified, layer it on top of defaults.
+        if instrument is not None:
+            preset = INSTRUMENTS.get(instrument)
+            if preset is None:
+                raise ValueError(
+                    f"Unknown instrument: {instrument!r}. "
+                    f"Use Score.list_instruments() to see available presets."
+                )
+            _defaults.update(preset)
+
+        # Collect explicitly-provided kwargs (non-None) and override defaults.
+        explicit = {}
+        _locals = {
+            "synth": synth, "envelope": envelope, "volume": volume,
+            "reverb": reverb, "reverb_decay": reverb_decay,
+            "reverb_type": reverb_type,
+            "delay": delay, "delay_time": delay_time,
+            "delay_feedback": delay_feedback,
+            "lowpass": lowpass, "lowpass_q": lowpass_q,
+            "distortion": distortion, "distortion_drive": distortion_drive,
+            "legato": legato, "glide": glide,
+            "chorus": chorus, "chorus_rate": chorus_rate,
+            "chorus_depth": chorus_depth,
+            "swing": swing, "humanize": humanize,
+            "sidechain": sidechain, "sidechain_release": sidechain_release,
+            "detune": detune, "pan": pan, "spread": spread,
+        }
+        for k, v in _locals.items():
+            if v is not None:
+                explicit[k] = v
+
+        merged = {**_defaults, **explicit}
+
+        p = Part(name, **merged)
         self.parts[name] = p
         return p
 
+    @classmethod
+    def list_instruments(cls) -> list:
+        """Return a sorted list of available instrument preset names.
+
+        Example::
+
+            Score.list_instruments()
+            # ['808_bass', 'acid_bass', 'acoustic_guitar', ...]
+        """
+        return sorted(INSTRUMENTS.keys())
+
     def add_pattern(self, pattern, repeats: int = 1) -> "Score":
         """Add a drum pattern to this score.
 
@@ -1904,46 +2235,85 @@ class Score:
         fill_pattern = Pattern.fill(name)
         return self.add_pattern(fill_pattern, repeats=1)
 
-    def drums(self, preset: str, repeats: int = 4, fill: str = None,
-              fill_every: int = None) -> "Score":
-        """Add a drum pattern by preset name, with optional auto-fills.
 
-        Shorthand for ``score.add_pattern(Pattern.preset(name), repeats=n)``.
+    # Drum sound groups for split mode
+    _DRUM_GROUPS = {
+        "kick": {DrumSound.KICK.value},
+        "snare": {DrumSound.SNARE.value, DrumSound.RIMSHOT.value, DrumSound.CLAP.value},
+        "hats": {DrumSound.CLOSED_HAT.value, DrumSound.OPEN_HAT.value, DrumSound.PEDAL_HAT.value},
+        "toms": {DrumSound.LOW_TOM.value, DrumSound.MID_TOM.value, DrumSound.HIGH_TOM.value},
+        "cymbals": {DrumSound.CRASH.value, DrumSound.RIDE.value, DrumSound.RIDE_BELL.value},
+        "percussion": {DrumSound.COWBELL.value, DrumSound.CLAVE.value, DrumSound.SHAKER.value,
+                       DrumSound.TAMBOURINE.value, DrumSound.CONGA_HIGH.value, DrumSound.CONGA_LOW.value,
+                       DrumSound.BONGO_HIGH.value, DrumSound.BONGO_LOW.value, DrumSound.TIMBALE_HIGH.value,
+                       DrumSound.TIMBALE_LOW.value, DrumSound.AGOGO_HIGH.value, DrumSound.AGOGO_LOW.value,
+                       DrumSound.GUIRO.value, DrumSound.MARACAS.value},
+    }
+
+    def drums(self, preset: str, repeats: int = 4, fill: str = None,
+              fill_every: int = None, split: bool = False) -> "Score":
+        """Add a drum pattern by preset name, with optional auto-fills.
 
         Args:
             preset: Pattern preset name (e.g. ``"bossa nova"``, ``"rock"``).
             repeats: Number of times to repeat (default 4).
-            fill: Optional fill name. When provided, groove bars are
-                periodically replaced with the named fill pattern.
-            fill_every: Replace every Nth bar with a fill. If *fill* is
-                provided but *fill_every* is not, defaults to filling only
-                the last bar.
+            fill: Optional fill name.
+            fill_every: Replace every Nth bar with a fill.
+            split: If True, create separate Parts for kick, snare, hats,
+                toms, cymbals, and percussion — each with independent
+                effects. Access via ``score.parts["kick"]``, etc.
 
         Returns:
             Self for chaining.
 
         Example::
 
-            >>> score = Score("4/4", bpm=140)
-            >>> score.drums("bossa nova", repeats=4)
+            >>> score.drums("rock", repeats=4, split=True)
+            >>> score.parts["snare"].reverb_mix = 0.3
+            >>> score.parts["hats"].lowpass = 6000
         """
         if fill is None:
-            return self.add_pattern(Pattern.preset(preset), repeats=repeats)
+            self.add_pattern(Pattern.preset(preset), repeats=repeats)
+        else:
+            groove = Pattern.preset(preset)
+            fill_pattern = Pattern.fill(fill)
+            if fill_every is None:
+                fill_every = repeats
+            for bar in range(1, repeats + 1):
+                if bar % fill_every == 0:
+                    self.add_pattern(fill_pattern, repeats=1)
+                else:
+                    self.add_pattern(groove, repeats=1)
 
-        groove = Pattern.preset(preset)
-        fill_pattern = Pattern.fill(fill)
+        if split:
+            self._split_drums()
 
-        if fill_every is None:
-            # Fill only the last bar
-            fill_every = repeats
-
-        for bar in range(1, repeats + 1):
-            if bar % fill_every == 0:
-                self.add_pattern(fill_pattern, repeats=1)
-            else:
-                self.add_pattern(groove, repeats=1)
         return self
 
+    def _split_drums(self):
+        """Move drum hits from the 'drums' Part into separate group Parts."""
+        drums_part = self.parts.get("drums")
+        if not drums_part:
+            return
+
+        all_hits = list(drums_part._drum_hits)
+        pattern_beats = drums_part._drum_pattern_beats
+        drums_part._drum_hits.clear()
+        drums_part._drum_pattern_beats = 0.0
+
+        for group_name, sound_values in self._DRUM_GROUPS.items():
+            group_hits = [h for h in all_hits if h.sound.value in sound_values]
+            if group_hits:
+                if group_name not in self.parts:
+                    self.parts[group_name] = Part(group_name, synth="sine", volume=0.7)
+                p = self.parts[group_name]
+                p._drum_hits.extend(group_hits)
+                p._drum_pattern_beats = max(p._drum_pattern_beats, pattern_beats)
+
+        # Remove empty drums Part
+        if not drums_part._drum_hits and "drums" in self.parts:
+            del self.parts["drums"]
+
     def add(self, tone_or_chord, duration=Duration.QUARTER) -> "Score":
         """Add a note to the default (unnamed) part.
 
@@ -2163,3 +2533,297 @@ class Score:
             f.write(b"MTrk")
             f.write(struct.pack(">I", len(events)))
             f.write(events)
+
+    # ── MIDI Import ──────────────────────────────────────────────────────
+
+    @classmethod
+    def from_midi(cls, path, synth="sine", envelope="pluck") -> "Score":
+        """Import a Standard MIDI File into a Score.
+
+        Reads notes, tempo, and time signature from any Type 0 or Type 1
+        MIDI file. Each MIDI channel becomes a named Part. Channel 10
+        (drums) becomes drum hits.
+
+        Args:
+            path: Path to a .mid file.
+            synth: Default synth for all parts (default "sine").
+            envelope: Default envelope for all parts (default "pluck").
+
+        Returns:
+            A Score with Parts populated from the MIDI data.
+
+        Example::
+
+            >>> score = Score.from_midi("song.mid")
+            >>> score.parts["ch1"].synth = "saw"
+            >>> score.parts["ch1"].reverb_mix = 0.3
+        """
+        midi = _parse_midi(path)
+
+        # Compute BPM from tempo (microseconds per beat)
+        bpm = round(60_000_000 / midi["tempo"])
+
+        # Build time signature string
+        ts_num, ts_den = midi["time_sig"]
+        ts_str = f"{ts_num}/{ts_den}"
+
+        score = cls(time_signature=ts_str, bpm=bpm)
+        tpb = midi["ticks_per_beat"]
+
+        # Build reverse DrumSound lookup: MIDI note number -> DrumSound
+        _drum_by_note = {}
+        for ds in DrumSound:
+            # First one wins (SHAKER and MARACAS both map to 70)
+            if ds.value not in _drum_by_note:
+                _drum_by_note[ds.value] = ds
+
+        # Collect note events per channel from all tracks
+        # Each entry: (abs_tick, 'on'/'off', pitch, velocity)
+        channel_events: dict[int, list] = {}
+        for track_events in midi["tracks"]:
+            for ev in track_events:
+                abs_tick, etype, channel, data = ev
+                if etype in ("note_on", "note_off"):
+                    if channel not in channel_events:
+                        channel_events[channel] = []
+                    channel_events[channel].append(ev)
+
+        for ch in sorted(channel_events.keys()):
+            events = sorted(channel_events[ch], key=lambda e: e[0])
+            is_drum = (ch == 9)  # channel 10 in 0-indexed
+
+            if is_drum:
+                # Convert to _Hit objects
+                for ev in events:
+                    abs_tick, etype, channel, data = ev
+                    if etype == "note_on" and data["velocity"] > 0:
+                        pitch = data["pitch"]
+                        beat_pos = abs_tick / tpb
+                        velocity = data["velocity"]
+                        drum_sound = _drum_by_note.get(pitch)
+                        if drum_sound is not None:
+                            score._drum_hits.append(
+                                _Hit(drum_sound, beat_pos, velocity))
+            else:
+                # Melodic channel: pair note_on/note_off to get durations
+                active: dict[int, tuple] = {}  # pitch -> (on_tick, velocity)
+                completed = []  # (beat_pos, pitch, velocity, duration_beats)
+
+                for ev in events:
+                    abs_tick, etype, channel_num, data = ev
+                    pitch = data["pitch"]
+                    vel = data["velocity"]
+
+                    if etype == "note_on" and vel > 0:
+                        active[pitch] = (abs_tick, vel)
+                    else:
+                        # note_off or note_on with vel=0
+                        if pitch in active:
+                            on_tick, on_vel = active.pop(pitch)
+                            dur_ticks = abs_tick - on_tick
+                            if dur_ticks > 0:
+                                beat_pos = on_tick / tpb
+                                dur_beats = dur_ticks / tpb
+                                completed.append(
+                                    (beat_pos, pitch, on_vel, dur_beats))
+
+                if not completed:
+                    continue
+
+                completed.sort(key=lambda x: (x[0], x[1]))
+
+                part_name = f"ch{ch + 1}"
+                part = score.part(part_name, synth=synth, envelope=envelope)
+
+                # Walk through notes, inserting rests for gaps
+                cursor = 0.0  # current beat position
+                for beat_pos, pitch, velocity, dur_beats in completed:
+                    gap = beat_pos - cursor
+                    if gap > 0.001:  # tolerance for floating point
+                        part.notes.append(Rest(_RawDuration(gap)))
+                    from .tones import Tone
+                    tone = Tone.from_midi(pitch)
+                    part.notes.append(
+                        Note(tone=tone, duration=_RawDuration(dur_beats),
+                             velocity=velocity))
+                    cursor = beat_pos + dur_beats
+
+        return score
+
+
+# ── MIDI File Parser ─────────────────────────────────────────────────────
+
+
+def _read_vlq(data, pos):
+    """Read a MIDI variable-length quantity.
+
+    Returns:
+        (value, new_pos) tuple.
+    """
+    value = 0
+    while True:
+        byte = data[pos]
+        value = (value << 7) | (byte & 0x7F)
+        pos += 1
+        if not (byte & 0x80):
+            break
+    return value, pos
+
+
+def _parse_midi(path):
+    """Parse a Standard MIDI File (Type 0 or Type 1).
+
+    Returns a dict with:
+        - ticks_per_beat: int
+        - tempo: int (microseconds per beat, default 500000 = 120 bpm)
+        - time_sig: (numerator, denominator)
+        - tracks: list of lists of events
+
+    Each event is a tuple: (abs_tick, type_str, channel, data_dict)
+    where type_str is 'note_on' or 'note_off' and data_dict has
+    'pitch' and 'velocity' keys.
+    """
+    with open(path, "rb") as f:
+        raw = f.read()
+
+    pos = 0
+
+    # ── Header chunk ──
+    if raw[pos:pos + 4] != b"MThd":
+        raise ValueError("Not a MIDI file (missing MThd header)")
+    pos += 4
+    header_len = struct.unpack(">I", raw[pos:pos + 4])[0]
+    pos += 4
+    fmt, num_tracks, ticks_per_beat = struct.unpack(">HHH", raw[pos:pos + 6])
+    pos += header_len  # usually 6
+
+    if fmt > 1:
+        raise ValueError(f"MIDI format {fmt} not supported (only 0 and 1)")
+
+    tempo = 500000  # default 120 BPM
+    time_sig = (4, 4)  # default
+    tracks = []
+
+    # ── Track chunks ──
+    for _ in range(num_tracks):
+        if raw[pos:pos + 4] != b"MTrk":
+            raise ValueError("Expected MTrk chunk")
+        pos += 4
+        track_len = struct.unpack(">I", raw[pos:pos + 4])[0]
+        pos += 4
+        track_end = pos + track_len
+
+        track_events = []
+        abs_tick = 0
+        running_status = 0
+
+        while pos < track_end:
+            # Read delta time
+            delta, pos = _read_vlq(raw, pos)
+            abs_tick += delta
+
+            # Read event
+            byte = raw[pos]
+
+            if byte == 0xFF:
+                # Meta event
+                pos += 1
+                meta_type = raw[pos]
+                pos += 1
+                meta_len, pos = _read_vlq(raw, pos)
+                meta_data = raw[pos:pos + meta_len]
+                pos += meta_len
+
+                if meta_type == 0x51 and meta_len == 3:
+                    # Tempo: 3 bytes, microseconds per beat
+                    tempo = (meta_data[0] << 16) | (meta_data[1] << 8) | meta_data[2]
+                elif meta_type == 0x58 and meta_len >= 2:
+                    # Time signature: nn dd cc bb
+                    ts_num = meta_data[0]
+                    ts_den = 2 ** meta_data[1]
+                    time_sig = (ts_num, ts_den)
+                # End of track (0x2F) and others: just skip
+
+            elif byte == 0xF0 or byte == 0xF7:
+                # SysEx event
+                pos += 1
+                sysex_len, pos = _read_vlq(raw, pos)
+                pos += sysex_len
+
+            elif byte & 0x80:
+                # Channel message with status byte
+                status = byte
+                running_status = status
+                pos += 1
+                msg_type = status & 0xF0
+                channel = status & 0x0F
+
+                if msg_type == 0x90:
+                    # Note On
+                    pitch = raw[pos]; pos += 1
+                    vel = raw[pos]; pos += 1
+                    if vel == 0:
+                        track_events.append(
+                            (abs_tick, "note_off", channel,
+                             {"pitch": pitch, "velocity": 0}))
+                    else:
+                        track_events.append(
+                            (abs_tick, "note_on", channel,
+                             {"pitch": pitch, "velocity": vel}))
+                elif msg_type == 0x80:
+                    # Note Off
+                    pitch = raw[pos]; pos += 1
+                    vel = raw[pos]; pos += 1
+                    track_events.append(
+                        (abs_tick, "note_off", channel,
+                         {"pitch": pitch, "velocity": vel}))
+                elif msg_type in (0xA0, 0xB0, 0xE0):
+                    # Aftertouch, Control Change, Pitch Bend: 2 data bytes
+                    pos += 2
+                elif msg_type in (0xC0, 0xD0):
+                    # Program Change, Channel Pressure: 1 data byte
+                    pos += 1
+                else:
+                    # Unknown channel message, skip 2 bytes as safe default
+                    pos += 2
+            else:
+                # Running status (no status byte, reuse previous)
+                if running_status == 0:
+                    # No previous status, skip byte
+                    pos += 1
+                    continue
+                msg_type = running_status & 0xF0
+                channel = running_status & 0x0F
+
+                if msg_type == 0x90:
+                    pitch = raw[pos]; pos += 1
+                    vel = raw[pos]; pos += 1
+                    if vel == 0:
+                        track_events.append(
+                            (abs_tick, "note_off", channel,
+                             {"pitch": pitch, "velocity": 0}))
+                    else:
+                        track_events.append(
+                            (abs_tick, "note_on", channel,
+                             {"pitch": pitch, "velocity": vel}))
+                elif msg_type == 0x80:
+                    pitch = raw[pos]; pos += 1
+                    vel = raw[pos]; pos += 1
+                    track_events.append(
+                        (abs_tick, "note_off", channel,
+                         {"pitch": pitch, "velocity": vel}))
+                elif msg_type in (0xA0, 0xB0, 0xE0):
+                    pos += 2
+                elif msg_type in (0xC0, 0xD0):
+                    pos += 1
+                else:
+                    pos += 2
+
+        tracks.append(track_events)
+
+    return {
+        "ticks_per_beat": ticks_per_beat,
+        "tempo": tempo,
+        "time_sig": time_sig,
+        "tracks": tracks,
+    }

test_pytheory.py

@@ -5312,7 +5312,7 @@ def test_supersaw_wave():
 @needs_portaudio
 def test_all_synths_in_enum():
     from pytheory.play import Synth
-    assert len(Synth) == 10
+    assert len(Synth) == 13
     for s in Synth:
         wave = s(440, n_samples=1000)
         assert len(wave) == 1000
@@ -6324,3 +6324,204 @@ def test_recommend_fitness_descending():
     results = Scale.recommend("C", "D", "E", "F#", "G")
     for i in range(len(results) - 1):
         assert results[i][2] >= results[i + 1][2]
+
+
+# ── MIDI Import (Score.from_midi) ────────────────────────────────────────
+
+
+def test_from_midi_basic(tmp_path):
+    """Create a simple MIDI with save_midi, re-import with from_midi."""
+    from pytheory import Score, Duration, Tone
+    score = Score("4/4", bpm=120)
+    score.add(Tone.from_string("C4"), Duration.QUARTER)
+    score.add(Tone.from_string("E4"), Duration.QUARTER)
+    score.add(Tone.from_string("G4"), Duration.QUARTER)
+
+    midi_path = str(tmp_path / "basic.mid")
+    score.save_midi(midi_path)
+
+    imported = Score.from_midi(midi_path)
+    # Should have at least one part with notes
+    assert len(imported.parts) >= 1
+    total_notes = sum(
+        1 for p in imported.parts.values()
+        for n in p.notes if n.tone is not None
+    )
+    assert total_notes == 3
+
+
+def test_from_midi_tempo(tmp_path):
+    """Verify BPM is preserved through save/import."""
+    from pytheory import Score, Duration, Tone
+    score = Score("4/4", bpm=140)
+    score.add(Tone.from_string("A4"), Duration.QUARTER)
+
+    midi_path = str(tmp_path / "tempo.mid")
+    score.save_midi(midi_path)
+
+    imported = Score.from_midi(midi_path)
+    assert imported.bpm == 140
+
+
+def test_from_midi_roundtrip(tmp_path):
+    """Save a progression as MIDI, import it, check parts/notes."""
+    from pytheory import Score, Duration, Tone
+    score = Score("3/4", bpm=100)
+    score.add(Tone.from_string("C4"), Duration.QUARTER)
+    score.add(Tone.from_string("D4"), Duration.QUARTER)
+    score.add(Tone.from_string("E4"), Duration.QUARTER)
+    score.add(Tone.from_string("F4"), Duration.QUARTER)
+
+    midi_path = str(tmp_path / "roundtrip.mid")
+    score.save_midi(midi_path)
+
+    imported = Score.from_midi(midi_path)
+    assert imported.bpm == 100
+    assert imported.time_signature == TimeSignature(3, 4)
+    total_notes = sum(
+        1 for p in imported.parts.values()
+        for n in p.notes if n.tone is not None
+    )
+    assert total_notes == 4
+
+
+def test_from_midi_velocity(tmp_path):
+    """Verify velocity is preserved through save/import."""
+    from pytheory import Score, Duration, Tone
+    score = Score("4/4", bpm=120)
+    # save_midi uses a fixed velocity param, default 100
+    score.add(Tone.from_string("C4"), Duration.QUARTER)
+    score.add(Tone.from_string("E4"), Duration.HALF)
+
+    midi_path = str(tmp_path / "velocity.mid")
+    score.save_midi(midi_path, velocity=80)
+
+    imported = Score.from_midi(midi_path)
+    sounding = [
+        n for p in imported.parts.values()
+        for n in p.notes if n.tone is not None
+    ]
+    assert len(sounding) == 2
+    for n in sounding:
+        assert n.velocity == 80
+
+
+def test_from_midi_drums(tmp_path):
+    """Verify drum hits survive a roundtrip."""
+    from pytheory import Score, Pattern
+    score = Score("4/4", bpm=120)
+    score.add_pattern(Pattern.preset("rock"), repeats=1)
+
+    midi_path = str(tmp_path / "drums.mid")
+    score.save_midi(midi_path)
+
+    imported = Score.from_midi(midi_path)
+    assert len(imported._drum_hits) > 0
+
+
+def test_from_midi_time_signature(tmp_path):
+    """Verify time signature is preserved."""
+    from pytheory import Score, Duration, Tone
+    score = Score("6/8", bpm=150)
+    score.add(Tone.from_string("C4"), Duration.QUARTER)
+
+    midi_path = str(tmp_path / "timesig.mid")
+    score.save_midi(midi_path)
+
+    imported = Score.from_midi(midi_path)
+    assert imported.time_signature == TimeSignature(6, 8)
+    assert imported.bpm == 150
+
+
+def test_from_midi_note_durations(tmp_path):
+    """Verify note durations are approximately preserved."""
+    from pytheory import Score, Duration, Tone
+    score = Score("4/4", bpm=120)
+    score.add(Tone.from_string("C4"), Duration.WHOLE)    # 4 beats
+    score.add(Tone.from_string("E4"), Duration.HALF)     # 2 beats
+
+    midi_path = str(tmp_path / "durations.mid")
+    score.save_midi(midi_path)
+
+    imported = Score.from_midi(midi_path)
+    sounding = [
+        n for p in imported.parts.values()
+        for n in p.notes if n.tone is not None
+    ]
+    assert len(sounding) == 2
+    assert abs(sounding[0].beats - 4.0) < 0.01
+    assert abs(sounding[1].beats - 2.0) < 0.01
+
+
+# ── Instrument presets ────────────────────────────────────────────────────────
+
+def test_instrument_piano():
+    from pytheory import Score, Duration
+    score = Score("4/4", bpm=120)
+    p = score.part("p", instrument="piano")
+    assert p.synth == "fm"
+    assert p.envelope == "piano"
+    assert p.detune == 5
+    assert p.lowpass == 6000
+    assert p.chorus_mix == 0.1
+
+
+def test_instrument_violin():
+    from pytheory import Score
+    score = Score("4/4", bpm=120)
+    p = score.part("v", instrument="violin")
+    assert p.synth == "strings_synth"
+    assert p.envelope == "strings"
+    assert p.humanize == 0.15
+    assert p.lowpass == 5000
+
+
+def test_instrument_override():
+    from pytheory import Score
+    score = Score("4/4", bpm=120)
+    # Explicit synth overrides the preset's "fm"
+    p = score.part("p", instrument="piano", synth="saw")
+    assert p.synth == "saw"
+    # Other preset values still apply
+    assert p.envelope == "piano"
+    assert p.detune == 5
+
+
+def test_instrument_unknown_raises():
+    from pytheory import Score
+    score = Score("4/4", bpm=120)
+    with pytest.raises(ValueError, match="Unknown instrument"):
+        score.part("x", instrument="kazoo")
+
+
+def test_list_instruments():
+    from pytheory import Score, INSTRUMENTS
+    result = Score.list_instruments()
+    assert isinstance(result, list)
+    assert result == sorted(result)
+    assert "piano" in result
+    assert "violin" in result
+    assert "808_bass" in result
+    assert len(result) == len(INSTRUMENTS)
+
+
+def test_instrument_effects():
+    from pytheory import Score
+    score = Score("4/4", bpm=120)
+    p = score.part("c", instrument="celesta")
+    assert p.reverb_mix == 0.3
+    assert p.reverb_type == "plate"
+    assert p.synth == "fm"
+    assert p.envelope == "bell"
+
+
+def test_instrument_808_bass():
+    from pytheory import Score
+    score = Score("4/4", bpm=120)
+    p = score.part("b", instrument="808_bass")
+    assert p.distortion_mix == 0.4
+    assert p.distortion_drive == 2.5
+    assert p.lowpass == 200
+    assert p.lowpass_q == 1.5
+    assert p.synth == "sine"
+    assert p.envelope == "pluck"

uv.lock

@@ -707,7 +707,7 @@ wheels = [
 
 [[package]]
 name = "pytheory"
-version = "0.28.2"
+version = "0.31.0"
 source = { editable = "." }
 dependencies = [
     { name = "numeral" },