v0.38.1: Dynamic curves (crescendo, decrescendo, swell, dynamics)

Part.crescendo(), Part.decrescendo(), Part.swell(), and Part.dynamics()
for velocity ramps and custom curves across note sequences.

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

CHANGELOG.md

@@ -2,6 +2,34 @@
 
 All notable changes to PyTheory are documented here.
 
+## 0.38.1
+
+- **Dynamic curves** — `Part.crescendo()`, `Part.decrescendo()`,
+  `Part.swell()`, and `Part.dynamics()` for velocity ramps and custom
+  curves across a sequence of notes
+
+## 0.38.0
+
+- **Articulations** — `staccato`, `legato`, `marcato`, `tenuto`, `accent`,
+  `fermata` via `articulation=` on `Part.add()` and `Part.hold()`
+- **`Part.hit()`** — place individual drum sounds in a Part's note stream
+  with articulation, velocity, and effects support
+- **5 new djembe patterns** — dununba, tiriba, yankadi, djansa, mendiani
+- **3 new djembe fills** — djembe call, djembe roll, djembe break (30 fills total)
+- **Cross-choke drum damping** — striking one sound fades out related sounds
+  (djembe, hi-hats, cajón, doumbek)
+- **Improved djembe slap** — dry goatskin pop instead of snare-like noise
+
+## 0.37.0
+
+- **5 new djembe patterns** — dununba, tiriba, yankadi, djansa, mendiani
+- **3 new djembe fills** — djembe call, djembe roll, djembe break (30 fills total)
+- **Cross-choke drum damping** — striking one sound on a hand drum fades
+  out the ring of related sounds (djembe slap kills bass resonance, closed
+  hat chokes open hat, cajón slap dampens bass, doumbek tek dampens dum)
+- **Improved djembe slap** — dry, high-pitched goatskin pop instead of
+  snare-like noise rattle
+
 ## 0.36.6
 
 - **6 new drum fills** — 3 cajón (flam, rumble, breakdown) and 3 metal

docs/guide/drums.rst

@@ -10,7 +10,7 @@ the genre -- they tell the listener's body how to move before a single
 melodic note is played.
 
 PyTheory includes a complete drum system -- 51 synthesized percussion
-sounds, 80+ pattern presets across dozens of genres, and 27 fill presets.
+sounds, 85+ pattern presets across dozens of genres, and 30 fill presets.
 Every sound is generated from waveforms; no samples needed.
 
 Drum Sounds
@@ -252,14 +252,15 @@ ending and a new one is about to begin. Without fills, a drum pattern
 just loops. With them, it breathes and has structure.
 
 ``Pattern.fill()`` loads a 1-bar drum fill -- a short break that
-transitions between sections. 27 fill presets are available:
+transitions between sections. 30 fill presets are available:
 
 .. code-block:: pycon
 
    >>> Pattern.list_fills()
    ['afrobeat', 'blast', 'bossa nova', 'breakdown', 'buildup',
     'cajon breakdown', 'cajon flam', 'cajon rumble',
-    'cumbia', 'disco', 'funk', 'highlife', 'hip hop', 'house',
+    'cumbia', 'disco', 'djembe break', 'djembe call', 'djembe roll',
+    'funk', 'highlife', 'hip hop', 'house',
     'jazz', 'jazz brush', 'metal', 'metal blast', 'metal cascade',
     'metal triplet', 'reggae', 'rock', 'rock crash',
     'salsa', 'samba', 'second line', 'trap']
@@ -435,14 +436,19 @@ central to the drum ensemble traditions of Mali, Guinea, and Senegal.
 **3 sounds** -- bass (open center strike), tone (edge strike), and
 slap (sharp edge strike).
 
-**3 patterns:** djembe (a basic accompanying rhythm), kuku (a
-traditional rhythm from Guinea associated with fishing), and soli (a
-solo/celebration rhythm).
+**8 patterns:** djembe (basic accompanying rhythm), kuku (Guinean harvest
+dance), soli (powerful Mandinka rhythm), dununba (heavy bass-driven),
+tiriba (joyful Susu rhythm), yankadi (gentle greeting/welcome), djansa
+(fast Malinke dance), mendiani (women's celebratory dance).
+
+**3 fills:** djembe call (bass-tone-slap conversation building to climax),
+djembe roll (rapid slaps accelerating into bass), djembe break (syncopated
+West African-style break).
 
 .. code-block:: python
 
    score = Score("4/4", bpm=120)
-   score.drums("djembe", repeats=4)
+   score.drums("djembe", repeats=8, fill="djembe call", fill_every=4)
 
 Metal Kit
 ~~~~~~~~~

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "pytheory"
-version = "0.36.6"
+version = "0.38.1"
 description = "Music Theory for Humans"
 readme = "README.md"
 license = "MIT"

pytheory/__init__.py

@@ -1,6 +1,6 @@
 """PyTheory: Music Theory for Humans."""
 
-__version__ = "0.36.6"
+__version__ = "0.38.1"
 
 from .tones import Tone, Interval
 from .systems import System, SYSTEMS, TET

pytheory/play.py

@@ -2890,29 +2890,27 @@ def _synth_djembe_tone(n_samples):
 def _synth_djembe_slap(n_samples):
     """Djembe slap — edge strike with fingers spread, sharp crack.
 
-    The highest, sharpest djembe sound. Fingers fan out on contact
-    creating a loud crack with minimal sustain.
+    The highest, sharpest djembe sound. A dry, high-pitched pop from
+    goatskin membrane — NOT a snare. Tight attack, very short decay,
+    skin character rather than wire rattle.
     """
     t = numpy.arange(n_samples, dtype=numpy.float32) / SAMPLE_RATE
-    # Sharp crack — mostly noise
-    crack_len = min(int(SAMPLE_RATE * 0.02), n_samples)
-    crack = _noise(crack_len) * _exp_decay(crack_len, 100) * 1.0
-    # Brief high-pitched ring
-    ring = numpy.sin(2 * numpy.pi * 600 * t) * _exp_decay(n_samples, 25) * 0.4
-    ring2 = numpy.sin(2 * numpy.pi * 1200 * t) * 0.2 * _exp_decay(n_samples, 35)
-    # Brief membrane pop
-    thump_len = min(int(SAMPLE_RATE * 0.02), n_samples)
-    thump_raw = _noise(thump_len)
-    if thump_len > 20:
-        bl, al = scipy.signal.butter(2, [300, 2000], btype='band', fs=SAMPLE_RATE)
-        thump = scipy.signal.lfilter(bl, al, numpy.pad(thump_raw, (0, max(0, n_samples - thump_len))))[:thump_len]
+    # High membrane pop — goatskin resonance, much higher than snare
+    pop = numpy.sin(2 * numpy.pi * 900 * t) * _exp_decay(n_samples, 50) * 0.5
+    pop2 = numpy.sin(2 * numpy.pi * 1600 * t) * _exp_decay(n_samples, 60) * 0.25
+    pop3 = numpy.sin(2 * numpy.pi * 2400 * t) * _exp_decay(n_samples, 80) * 0.12
+    # Very short filtered click — hand-on-skin transient, not noise rattle
+    click_len = min(int(SAMPLE_RATE * 0.008), n_samples)
+    click_raw = _noise(click_len)
+    if click_len > 20:
+        bl, al = scipy.signal.butter(2, 1800 / (SAMPLE_RATE / 2), btype='high')
+        click = scipy.signal.lfilter(bl, al, numpy.pad(click_raw, (0, max(0, n_samples - click_len))))[:click_len]
     else:
-        thump = thump_raw
-    thump *= _exp_decay(thump_len, 80) * 0.8
-    result = ring + ring2
-    result[:crack_len] += crack
-    result[:thump_len] += thump
-    return numpy.tanh(result * 1.7)
+        click = click_raw
+    click *= _exp_decay(click_len, 150) * 0.6
+    result = pop + pop2 + pop3
+    result[:click_len] += click
+    return numpy.tanh(result * 1.5)
 
 
 def _synth_guiro(n_samples):
@@ -4147,10 +4145,48 @@ def _render_notes_to_buf(notes, buf, samples_per_beat, total_samples,
                 start += _rnd.randint(-max_offset, max_offset)
                 start = max(0, start)
             dur_ms = note.beats * 60_000 / bpm
+            # Articulation: adjust duration and velocity
+            art = getattr(note, 'articulation', '')
+            art_vel_mult = 1.0
+            art_attack_mult = 1.0  # multiplier for envelope attack
+            if art == 'staccato':
+                dur_ms *= 0.4  # short and bouncy
+            elif art == 'legato':
+                dur_ms *= 1.15  # slight overlap into next note
+            elif art == 'marcato':
+                art_vel_mult = 1.25  # heavier
+                art_attack_mult = 0.3  # sharper attack
+            elif art == 'tenuto':
+                art_attack_mult = 1.8  # softer attack, full duration
+            elif art == 'accent':
+                art_vel_mult = 1.2
+            elif art == 'fermata':
+                dur_ms *= 1.5  # held longer
             n_samples = int(SAMPLE_RATE * dur_ms / 1000)
             if start + n_samples > total_samples:
                 n_samples = total_samples - start
             if n_samples > 0 and start >= 0:
+                # Drum hit via Part.hit() — use drum synth directly
+                from .rhythm import _DrumTone
+                if isinstance(note.tone, _DrumTone):
+                    drum_wave = _render_drum_hit(note.tone.sound.value, n_samples)
+                    mixed = drum_wave.astype(numpy.float32)
+                    # Staccato fade-out for drums
+                    if art == 'staccato':
+                        fade_len = min(int(SAMPLE_RATE * 0.01), len(mixed))
+                        if fade_len > 0:
+                            mixed[-fade_len:] *= numpy.linspace(1.0, 0.0, fade_len).astype(numpy.float32)
+                    vel = getattr(note, 'velocity', 100)
+                    vel = min(127, int(vel * art_vel_mult))
+                    if humanize > 0.0:
+                        vel_jitter = int(humanize * 15)
+                        vel = max(1, min(127, vel + _rnd.randint(-vel_jitter, vel_jitter)))
+                    vel_scale = vel / 127.0
+                    end = min(start + len(mixed), total_samples)
+                    buf[start:end] += mixed[:end - start] * volume * vel_scale
+                    if not getattr(note, '_hold', False):
+                        beat_pos += note.beats
+                    continue
                 # Get pitches
                 if hasattr(note.tone, 'tones'):
                     pitches = [t.pitch(temperament=temperament, reference_pitch=reference_pitch) for t in note.tone.tones]
@@ -4251,11 +4287,18 @@ def _render_notes_to_buf(notes, buf, samples_per_beat, total_samples,
                 if noise_mix > 0:
                     noise = numpy.random.uniform(-1, 1, n_samples).astype(numpy.float32)
                     mixed = mixed * (1.0 - noise_mix * 0.5) + noise * noise_mix * 0.5
-                # Amplitude envelope
-                if a > 0 or d > 0 or s < 1.0 or r > 0:
-                    mixed = _apply_envelope(mixed, a, d, s, r)
-                # Per-note velocity
+                # Amplitude envelope (articulation may adjust attack)
+                art_a = a * art_attack_mult
+                if art_a > 0 or d > 0 or s < 1.0 or r > 0:
+                    mixed = _apply_envelope(mixed, art_a, d, s, r)
+                # Staccato: apply a quick fade-out at the end
+                if art == 'staccato':
+                    fade_len = min(int(SAMPLE_RATE * 0.01), len(mixed))
+                    if fade_len > 0:
+                        mixed[-fade_len:] *= numpy.linspace(1.0, 0.0, fade_len).astype(numpy.float32)
+                # Per-note velocity (articulation may boost)
                 vel = getattr(note, 'velocity', 100)
+                vel = min(127, int(vel * art_vel_mult))
                 if humanize > 0.0:
                     vel_jitter = int(humanize * 15)
                     vel = max(1, min(127, vel + _rnd.randint(-vel_jitter, vel_jitter)))
@@ -4661,6 +4704,35 @@ def render_score(score):
                         part_stereo[fade_start:start, ch] *= fade
             _last_hit_start[sound_id] = start
 
+            # Cross-choke: a new hit on one sound dampens the ring of
+            # related sounds on the same instrument (e.g. djembe slap
+            # kills the bass resonance, closed hat kills open hat).
+            _CHOKE_GROUPS = {
+                # Djembe — any strike dampens the others
+                DrumSound.DJEMBE_BASS.value: (DrumSound.DJEMBE_TONE.value, DrumSound.DJEMBE_SLAP.value),
+                DrumSound.DJEMBE_TONE.value: (DrumSound.DJEMBE_BASS.value, DrumSound.DJEMBE_SLAP.value),
+                DrumSound.DJEMBE_SLAP.value: (DrumSound.DJEMBE_BASS.value, DrumSound.DJEMBE_TONE.value),
+                # Hi-hats — closed chokes open
+                DrumSound.CLOSED_HAT.value: (DrumSound.OPEN_HAT.value,),
+                DrumSound.PEDAL_HAT.value: (DrumSound.OPEN_HAT.value,),
+                # Cajón — slap dampens bass ring
+                DrumSound.CAJON_SLAP.value: (DrumSound.CAJON_BASS.value,),
+                DrumSound.CAJON_TAP.value: (DrumSound.CAJON_BASS.value,),
+                # Doumbek — tek/ka dampen dum
+                DrumSound.DOUMBEK_TEK.value: (DrumSound.DOUMBEK_DUM.value,),
+                DrumSound.DOUMBEK_KA.value: (DrumSound.DOUMBEK_DUM.value,),
+            }
+            choke_targets = _CHOKE_GROUPS.get(sound_id, ())
+            for target_id in choke_targets:
+                if target_id in _last_hit_start:
+                    prev_start = _last_hit_start[target_id]
+                    fade_len = min(int(SAMPLE_RATE * 0.004), max(0, start - prev_start))
+                    if fade_len > 0 and start > 0:
+                        fade = numpy.linspace(1.0, 0.0, fade_len).astype(numpy.float32)
+                        fade_start = max(0, start - fade_len)
+                        for ch in range(2):
+                            part_stereo[fade_start:start, ch] *= fade
+
             remaining = total_samples - start
             hit_len = min(int(SAMPLE_RATE * 0.5), remaining)
             wave = _render_drum_hit(hit.sound.value, hit_len)

pytheory/rhythm.py

@@ -449,6 +449,7 @@ class Note:
     bend: float = 0.0
     bend_type: str = "smooth"  # "smooth" (log), "linear", "late"
     lyric: str = ""  # syllable for vocal synth
+    articulation: str = ""  # "", "staccato", "legato", "marcato", "tenuto", "accent", "fermata"
     _hold: bool = False  # if True, don't advance beat position
 
     @property
@@ -565,6 +566,17 @@ class DrumSound(Enum):
     METAL_HAT = 107      # tight, short, precise
 
 
+class _DrumTone:
+    """Wrapper so a DrumSound can be placed in a Part's note list."""
+    __slots__ = ('sound',)
+
+    def __init__(self, sound: DrumSound):
+        self.sound = sound
+
+    def pitch(self, **kwargs):
+        return -self.sound.value
+
+
 class _Hit:
     """A single drum hit at a specific position in a pattern."""
     __slots__ = ("sound", "position", "velocity")
@@ -1907,6 +1919,74 @@ Pattern._PRESETS["soli"] = dict(
     ],
 )
 
+# Dununba — heavy bass-driven rhythm (accompaniment djembe part)
+Pattern._PRESETS["dununba"] = dict(
+    name="dununba",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(JB, 0.0, 110), _h(JB, 0.5, 95),
+        _h(JT, 1.0, 75), _h(JB, 1.5, 100),
+        _h(JB, 2.0, 108), _h(JT, 2.5, 70),
+        _h(JB, 3.0, 105), _h(JB, 3.5, 90), _h(JT, 3.75, 65),
+    ],
+)
+
+# Tiriba — joyful Susu rhythm from Guinea
+Pattern._PRESETS["tiriba"] = dict(
+    name="tiriba",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(JT, 0.0, 85), _h(JS, 0.25, 95), _h(JT, 0.5, 80),
+        _h(JB, 1.0, 100), _h(JT, 1.5, 75),
+        _h(JS, 2.0, 92), _h(JT, 2.25, 78), _h(JT, 2.5, 80),
+        _h(JB, 3.0, 105), _h(JS, 3.5, 88), _h(JT, 3.75, 72),
+    ],
+)
+
+# Yankadi — gentle greeting/welcome rhythm from Guinea
+Pattern._PRESETS["yankadi"] = dict(
+    name="yankadi",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(JB, 0.0, 90), _h(JT, 0.5, 70),
+        _h(JT, 1.0, 72), _h(JS, 1.5, 85),
+        _h(JB, 2.0, 88), _h(JT, 2.5, 68),
+        _h(JS, 3.0, 82), _h(JT, 3.5, 65),
+    ],
+)
+
+# Djansa — fast Malinke dance rhythm
+Pattern._PRESETS["djansa"] = dict(
+    name="djansa",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(JS, 0.0, 100), _h(JT, 0.25, 72), _h(JT, 0.5, 70),
+        _h(JB, 0.75, 95),
+        _h(JS, 1.0, 98), _h(JT, 1.25, 68), _h(JB, 1.5, 92),
+        _h(JS, 2.0, 102), _h(JT, 2.25, 75), _h(JT, 2.5, 72),
+        _h(JB, 2.75, 90),
+        _h(JS, 3.0, 105), _h(JT, 3.25, 70), _h(JB, 3.5, 95),
+        _h(JS, 3.75, 88),
+    ],
+)
+
+# Mendiani — women's dance rhythm, celebratory
+Pattern._PRESETS["mendiani"] = dict(
+    name="mendiani",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(JB, 0.0, 100), _h(JT, 0.25, 65), _h(JS, 0.5, 90),
+        _h(JT, 1.0, 70), _h(JB, 1.5, 95), _h(JT, 1.75, 68),
+        _h(JS, 2.0, 92), _h(JT, 2.5, 72), _h(JS, 2.75, 85),
+        _h(JB, 3.0, 105), _h(JT, 3.25, 65), _h(JS, 3.5, 95),
+    ],
+)
+
 # ── Fill presets ──────────────────────────────────────────────────────────
 
 Pattern._FILLS["rock"] = dict(
@@ -2292,6 +2372,57 @@ Pattern._FILLS["tabla call"] = dict(
     ],
 )
 
+# ── Djembe fills ─────────────────────────────────────────────────────────
+
+# Djembe call — bass-tone-slap conversation building to climax
+Pattern._FILLS["djembe call"] = dict(
+    name="djembe call fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(JB, 0.0, 100), _h(JT, 0.25, 70), _h(JT, 0.5, 72),
+        _h(JS, 0.75, 90),
+        _h(JB, 1.0, 95), _h(JT, 1.25, 68), _h(JS, 1.5, 88),
+        _h(JT, 1.75, 75),
+        _h(JS, 2.0, 100), _h(JS, 2.25, 95), _h(JT, 2.5, 78),
+        _h(JB, 2.75, 105),
+        _h(JS, 3.0, 110), _h(JT, 3.25, 80), _h(JS, 3.5, 112),
+        _h(JB, 3.75, 120),
+    ],
+)
+
+# Djembe roll — rapid slaps accelerating into bass
+Pattern._FILLS["djembe roll"] = dict(
+    name="djembe roll fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        # Accelerating slap roll
+        *[_h(JS, i * 0.125, 50 + i * 4) for i in range(16)],
+        # Bass accents punching through
+        _h(JB, 2.0, 105), _h(JB, 2.5, 108),
+        _h(JB, 3.0, 112), _h(JT, 3.25, 85),
+        _h(JB, 3.5, 115), _h(JS, 3.75, 100),
+    ],
+)
+
+# Djembe break — syncopated West African-style break
+Pattern._FILLS["djembe break"] = dict(
+    name="djembe break fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(JB, 0.0, 105), _h(JT, 0.25, 65), _h(JS, 0.5, 90),
+        _h(JT, 0.75, 70), _h(JB, 1.0, 100),
+        _h(JS, 1.25, 85), _h(JS, 1.5, 88),
+        _h(JB, 1.75, 95), _h(JT, 2.0, 72),
+        _h(JS, 2.25, 92), _h(JB, 2.5, 108),
+        _h(JT, 2.75, 68), _h(JS, 2.875, 55),
+        _h(JB, 3.0, 115), _h(JS, 3.25, 100),
+        _h(JB, 3.5, 118), _h(JB, 3.75, 120),
+    ],
+)
+
 # ── Cajón fills ──────────────────────────────────────────────────────────
 
 # Cajón flam run — slaps accelerating into bass hit
@@ -2505,7 +2636,8 @@ class Part:
         self._automation: list[tuple[float, dict]] = []  # (beat, {param: value})
 
     def add(self, tone_or_string, duration=Duration.QUARTER, *, velocity: int = 100,
-            bend: float = 0.0, bend_type: str = "smooth", lyric: str = "") -> "Part":
+            bend: float = 0.0, bend_type: str = "smooth", lyric: str = "",
+            articulation: str = "") -> "Part":
         """Add a note. Accepts Tone/Chord objects or note strings like ``"E5"``.
 
         Duration can be a ``Duration`` enum or a raw float (beats).
@@ -2513,6 +2645,10 @@ class Part:
         Bend specifies a pitch bend in semitones over the note duration
         (e.g. ``bend=2`` bends up a whole step, ``bend=-1`` bends down
         a half step). Used for guitar bends, sitar meends, slides.
+        Articulation changes how the note is played: ``"staccato"`` (short,
+        ~40% duration), ``"legato"`` (overlaps next note), ``"marcato"``
+        (heavy accent), ``"tenuto"`` (full duration, soft attack),
+        ``"accent"`` (velocity bump), ``"fermata"`` (held ~50% longer).
 
         Returns self for chaining.
         """
@@ -2523,11 +2659,13 @@ class Part:
             duration = _RawDuration(duration)
         self.notes.append(Note(tone=tone_or_string, duration=duration,
                                velocity=velocity, bend=bend,
-                               bend_type=bend_type, lyric=lyric))
+                               bend_type=bend_type, lyric=lyric,
+                               articulation=articulation))
         return self
 
     def hold(self, tone_or_string, duration=Duration.QUARTER, *, velocity: int = 100,
-             bend: float = 0.0, bend_type: str = "smooth", lyric: str = "") -> "Part":
+             bend: float = 0.0, bend_type: str = "smooth", lyric: str = "",
+             articulation: str = "") -> "Part":
         """Add a note without advancing the beat position.
 
         The note plays at the current position but the next note
@@ -2552,9 +2690,168 @@ class Part:
             duration = _RawDuration(duration)
         self.notes.append(Note(tone=tone_or_string, duration=duration,
                                velocity=velocity, bend=bend,
-                               bend_type=bend_type, lyric=lyric, _hold=True))
+                               bend_type=bend_type, lyric=lyric,
+                               articulation=articulation, _hold=True))
         return self
 
+    def hit(self, sound, duration=Duration.EIGHTH, *, velocity: int = 100,
+            articulation: str = "") -> "Part":
+        """Add a drum hit to this part.
+
+        Places a drum sound into the note stream so it goes through the
+        normal renderer — meaning articulations, humanize, and effects
+        all work on individual hits.
+
+        Args:
+            sound: A :class:`DrumSound` enum member (e.g. ``DrumSound.KICK``).
+            duration: How long the hit occupies in the timeline (default 8th note).
+            velocity: Hit loudness 1-127.
+            articulation: ``"accent"``, ``"staccato"``, ``"marcato"``, etc.
+
+        Example::
+
+            >>> drums = score.part("kit", synth="sine")
+            >>> drums.hit(DrumSound.KICK, Duration.QUARTER, articulation="accent")
+            >>> drums.hit(DrumSound.CLOSED_HAT, Duration.EIGHTH)
+        """
+        if isinstance(duration, (int, float)):
+            duration = _RawDuration(duration)
+        self.notes.append(Note(tone=_DrumTone(sound), duration=duration,
+                               velocity=velocity, articulation=articulation))
+        return self
+
+    def crescendo(self, notes, duration=Duration.QUARTER, *,
+                  start_vel: int = 40, end_vel: int = 110,
+                  articulation: str = "") -> "Part":
+        """Add notes with velocity ramping up (getting louder).
+
+        Args:
+            notes: List of note strings (e.g. ``["C4", "D4", "E4"]``).
+            duration: Duration for each note.
+            start_vel: Starting velocity (quiet).
+            end_vel: Ending velocity (loud).
+            articulation: Optional articulation for all notes.
+
+        Example::
+
+            >>> piano.crescendo(["C4","D4","E4","F4","G4"], Duration.QUARTER,
+            ...                 start_vel=40, end_vel=110)
+        """
+        return self.dynamics(notes, duration, velocities=(start_vel, end_vel),
+                             articulation=articulation)
+
+    def decrescendo(self, notes, duration=Duration.QUARTER, *,
+                    start_vel: int = 110, end_vel: int = 40,
+                    articulation: str = "") -> "Part":
+        """Add notes with velocity ramping down (getting quieter).
+
+        Args:
+            notes: List of note strings.
+            duration: Duration for each note.
+            start_vel: Starting velocity (loud).
+            end_vel: Ending velocity (quiet).
+            articulation: Optional articulation for all notes.
+
+        Example::
+
+            >>> piano.decrescendo(["G4","F4","E4","D4","C4"], Duration.QUARTER,
+            ...                   start_vel=110, end_vel=40)
+        """
+        return self.dynamics(notes, duration, velocities=(start_vel, end_vel),
+                             articulation=articulation)
+
+    def dynamics(self, notes, duration=Duration.QUARTER, *,
+                 velocities=None, articulation: str = "") -> "Part":
+        """Add notes with a velocity curve.
+
+        Args:
+            notes: List of note strings or Tone/Chord objects.
+            duration: Duration for each note (or list of durations).
+            velocities: Velocity curve — either a ``(start, end)`` tuple
+                for a linear ramp, or a list of ints (one per note).
+            articulation: Optional articulation for all notes (or list).
+
+        Example::
+
+            >>> # Linear ramp
+            >>> piano.dynamics(["C4","E4","G4","C5"], Duration.QUARTER,
+            ...                velocities=(50, 120))
+            >>> # Custom curve (swell and fade)
+            >>> piano.dynamics(["C4","D4","E4","F4","G4","F4","E4","D4"],
+            ...                Duration.EIGHTH,
+            ...                velocities=[50, 70, 90, 110, 110, 90, 70, 50])
+        """
+        n = len(notes)
+        if n == 0:
+            return self
+
+        # Resolve velocities
+        if velocities is None:
+            vels = [100] * n
+        elif isinstance(velocities, (tuple, list)) and len(velocities) == 2 and isinstance(velocities[0], (int, float)):
+            # (start, end) tuple — linear ramp
+            start_v, end_v = velocities
+            if n == 1:
+                vels = [int(start_v)]
+            else:
+                vels = [int(start_v + (end_v - start_v) * i / (n - 1))
+                        for i in range(n)]
+        else:
+            vels = list(velocities)
+
+        # Resolve durations
+        if isinstance(duration, (list, tuple)):
+            durs = list(duration)
+        else:
+            durs = [duration] * n
+
+        # Resolve articulations
+        if isinstance(articulation, (list, tuple)):
+            arts = list(articulation)
+        else:
+            arts = [articulation] * n
+
+        for note, vel, dur, art in zip(notes, vels, durs, arts):
+            vel = max(1, min(127, vel))
+            self.add(note, dur, velocity=vel, articulation=art)
+
+        return self
+
+    def swell(self, notes, duration=Duration.QUARTER, *,
+              low_vel: int = 40, peak_vel: int = 110,
+              articulation: str = "") -> "Part":
+        """Add notes that swell up then fade back down (< > shape).
+
+        The velocity ramps up to the midpoint then back down,
+        creating the classic orchestral swell.
+
+        Args:
+            notes: List of note strings.
+            duration: Duration for each note.
+            low_vel: Velocity at start and end.
+            peak_vel: Velocity at the peak (midpoint).
+            articulation: Optional articulation.
+
+        Example::
+
+            >>> strings.swell(["C4","D4","E4","F4","G4","F4","E4","D4"],
+            ...               Duration.QUARTER, low_vel=40, peak_vel=110)
+        """
+        n = len(notes)
+        if n <= 2:
+            return self.dynamics(notes, duration, velocities=[peak_vel] * n,
+                                 articulation=articulation)
+        mid = n // 2
+        vels = []
+        for i in range(n):
+            if i <= mid:
+                v = low_vel + (peak_vel - low_vel) * i / mid
+            else:
+                v = peak_vel - (peak_vel - low_vel) * (i - mid) / (n - 1 - mid)
+            vels.append(int(v))
+        return self.dynamics(notes, duration, velocities=vels,
+                             articulation=articulation)
+
     def set(self, **params) -> "Part":
         """Change effect parameters at the current beat position.
 

uv.lock

@@ -698,7 +698,7 @@ wheels = [
 
 [[package]]
 name = "pytheory"
-version = "0.36.6"
+version = "0.38.1"
 source = { editable = "." }
 dependencies = [
     { name = "numeral" },