v0.36.6: Cajón and metal drum fills

Add 6 new drum fills: cajon flam, cajon rumble, cajon breakdown,
metal triplet, metal blast, metal cascade. 27 fills total.

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

CHANGELOG.md

@@ -2,6 +2,17 @@
 
 All notable changes to PyTheory are documented here.
 
+## 0.36.6
+
+- **6 new drum fills** — 3 cajón (flam, rumble, breakdown) and 3 metal
+  (triplet, blast, cascade). 27 fills total.
+- Updated drums documentation with fill lists and examples
+
+## 0.36.5
+
+- **Duration arithmetic** — `Duration.WHOLE * 2`, `Duration.HALF + Duration.QUARTER`,
+  division, and reverse multiply all work now (previously raised TypeError)
+
 ## 0.36.3
 
 - **`Part.hold()`** — polyphonic overlap on a single part. Add notes

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 21 fill presets.
+sounds, 80+ pattern presets across dozens of genres, and 27 fill presets.
 Every sound is generated from waveforms; no samples needed.
 
 Drum Sounds
@@ -252,14 +252,16 @@ 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. 21 fill presets are available:
+transitions between sections. 27 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',
-    'jazz', 'jazz brush', 'metal', 'reggae', 'rock', 'rock crash',
+    'jazz', 'jazz brush', 'metal', 'metal blast', 'metal cascade',
+    'metal triplet', 'reggae', 'rock', 'rock crash',
     'salsa', 'samba', 'second line', 'trap']
 
    >>> fill = Pattern.fill("rock")
@@ -357,6 +359,15 @@ the pitch upward.
 and light classical), tabla solo, and tiri kita (fast ornamental
 pattern).
 
+**5 fills:** tihai (3x crescendo landing on sam), chakkardar (32nd
+triplet cascade into slam), tiri kita (rapid 16th-note dayan burst),
+bayan (deep bass bends showcase), tabla call (dayan/bayan call-and-response).
+
+.. code-block:: python
+
+   score.drums("teental", repeats=4, fill="tihai")
+   score.drums("keherwa", repeats=4, fill="chakkardar")
+
 .. code-block:: python
 
    score = Score("4/4", bpm=80)
@@ -447,10 +458,15 @@ metal blast (blast beat with china cymbal accents), metal groove (a
 half-time groove with double kick fills), and metal gallop (the
 classic triplet-feel gallop rhythm).
 
+**4 fills:** metal (double kick 16ths with descending toms), metal triplet
+(double kick triplets with snare accents), metal blast (alternating
+snare/kick 32nds into half-time crash), metal cascade (descending snare
+roll → kick roll → alternating → crash ending).
+
 .. code-block:: python
 
    score = Score("4/4", bpm=200)
-   score.drums("metal blast", repeats=4)
+   score.drums("metal blast", repeats=8, fill="metal cascade", fill_every=4)
 
 Cajón
 ~~~~~
@@ -459,15 +475,20 @@ The cajón is a box-shaped percussion instrument from Peru, now
 ubiquitous in acoustic and unplugged settings worldwide. Players sit
 on the box and strike the front face with their hands.
 
-**2 sounds** -- slap (sharp, snare-like) and tap (bass-like).
+**3 sounds** -- bass (deep center thump), slap (sharp, snare-like edge
+hit with wire buzz), and tap (light finger tap).
 
 **3 patterns:** cajon (basic groove), cajon rumba (flamenco-style rumba),
 and cajon folk (folk/acoustic pattern).
 
+**3 fills:** cajon flam (slaps accelerating into bass hits), cajon rumble
+(fast taps building to slap accents), cajon breakdown (syncopated
+bass-slap groove).
+
 .. code-block:: python
 
    score = Score("4/4", bpm=100)
-   score.drums("cajon", repeats=4)
+   score.drums("cajon", repeats=8, fill="cajon flam", fill_every=4)
 
 MIDI Export
 -----------

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "pytheory"
-version = "0.36.3"
+version = "0.36.6"
 description = "Music Theory for Humans"
 readme = "README.md"
 license = "MIT"

pytheory/__init__.py

@@ -1,6 +1,6 @@
 """PyTheory: Music Theory for Humans."""
 
-__version__ = "0.36.3"
+__version__ = "0.36.6"
 
 from .tones import Tone, Interval
 from .systems import System, SYSTEMS, TET

pytheory/play.py

@@ -1237,6 +1237,47 @@ def steel_drum_wave(hz, peak=SAMPLE_PEAK, n_samples=SAMPLE_RATE):
     return (peak * wave).astype(numpy.int16)
 
 
+def harmonium_wave(hz, peak=SAMPLE_PEAK, n_samples=SAMPLE_RATE):
+    """Harmonium — Indian pump organ, single free reed per note.
+
+    Unlike accordion (doubled musette reeds), the harmonium has one
+    reed per note — no beating, just a pure, nasal, reedy tone.
+    Constant bellows pressure, warm but slightly buzzy. The sound
+    of kirtan, qawwali, and devotional music.
+    """
+    t = numpy.arange(n_samples, dtype=numpy.float64) / SAMPLE_RATE
+    rng = numpy.random.default_rng(int(hz * 100) % 2**31)
+
+    # Single reed — odd harmonics stronger (like clarinet but warmer)
+    wave = numpy.zeros(n_samples, dtype=numpy.float64)
+    for n in range(1, 12):
+        f_n = hz * n
+        if f_n >= SAMPLE_RATE / 2:
+            break
+        amp = (1.0 / n) * (1.0 if n % 2 == 1 else 0.5)
+        phase = rng.uniform(0, 2 * numpy.pi)
+        wave += amp * numpy.sin(2 * numpy.pi * f_n * t + phase)
+
+    # Bellows pressure — gentle swell, slower than accordion
+    bellows = 0.9 + 0.1 * numpy.sin(2 * numpy.pi * 0.5 * t)
+    wave *= bellows
+
+    # Nasal character — slight midrange boost
+    import scipy.signal as _sig
+    center = min(1200, hz * 3)
+    lo = max(20, int(center - 300))
+    hi = min(SAMPLE_RATE // 2 - 1, int(center + 300))
+    if lo < hi:
+        bp, ap = _sig.butter(2, [lo, hi], btype='band', fs=SAMPLE_RATE)
+        nasal = _sig.lfilter(bp, ap, wave) * 0.2
+        wave += nasal
+
+    mx = numpy.abs(wave).max()
+    if mx > 0:
+        wave /= mx
+    return (peak * wave).astype(numpy.int16)
+
+
 def accordion_wave(hz, peak=SAMPLE_PEAK, n_samples=SAMPLE_RATE):
     """Accordion — bellows-driven free reeds.
 
@@ -1794,6 +1835,7 @@ class Synth(Enum):
     THEREMIN = "theremin_synth"
     KALIMBA = "kalimba_synth"
     STEEL_DRUM = "steel_drum_synth"
+    HARMONIUM = "harmonium_synth"
     ACCORDION = "accordion_synth"
     DIDGERIDOO = "didgeridoo_synth"
     BAGPIPE = "bagpipe_synth"
@@ -1825,7 +1867,7 @@ _SYNTH_FUNCTIONS = {
     "granular_synth": granular_wave, "vocal_synth": vocal_wave,
     "pedal_steel_synth": pedal_steel_wave, "theremin_synth": theremin_wave,
     "kalimba_synth": kalimba_wave, "steel_drum_synth": steel_drum_wave,
-    "accordion_synth": accordion_wave, "didgeridoo_synth": didgeridoo_wave,
+    "harmonium_synth": harmonium_wave, "accordion_synth": accordion_wave, "didgeridoo_synth": didgeridoo_wave,
     "bagpipe_synth": bagpipe_wave,
     "banjo_synth": banjo_wave, "mandolin_synth": mandolin_wave,
     "ukulele_synth": ukulele_wave,
@@ -2584,6 +2626,52 @@ def _synth_mridangam_tha(n_samples):
     return out
 
 
+def _synth_doumbek_dum(n_samples):
+    """Doumbek Dum — open center strike, deep and round."""
+    t = numpy.arange(n_samples, dtype=numpy.float32) / SAMPLE_RATE
+    freq = 80 + 40 * numpy.exp(-25 * t)
+    phase = 2 * numpy.pi * numpy.cumsum(freq) / SAMPLE_RATE
+    body = numpy.sin(phase) * _exp_decay(n_samples, 8) * 0.8
+    thump_len = min(int(SAMPLE_RATE * 0.04), n_samples)
+    import scipy.signal as _sig
+    thump = _noise(thump_len)
+    if thump_len > 20:
+        bl, al = _sig.butter(2, [50, 250], btype='band', fs=SAMPLE_RATE)
+        thump = _sig.lfilter(bl, al, numpy.pad(thump, (0, max(0, n_samples - thump_len))))[:thump_len].astype(numpy.float32)
+    thump *= _exp_decay(thump_len, 22) * 0.7
+    body[:thump_len] += thump
+    return numpy.tanh(body * 1.3).astype(numpy.float32)
+
+
+def _synth_doumbek_tek(n_samples):
+    """Doumbek Tek — sharp edge strike, bright and cutting."""
+    t = numpy.arange(n_samples, dtype=numpy.float32) / SAMPLE_RATE
+    ring = numpy.sin(2 * numpy.pi * 400 * t) * _exp_decay(n_samples, 22) * 0.5
+    ring2 = numpy.sin(2 * numpy.pi * 900 * t) * 0.3 * _exp_decay(n_samples, 30)
+    click_len = min(int(SAMPLE_RATE * 0.005), n_samples)
+    click = _noise(click_len) * _exp_decay(click_len, 300) * 0.9
+    import scipy.signal as _sig
+    if click_len > 10:
+        bl, al = _sig.butter(2, [2000, min(8000, SAMPLE_RATE // 2 - 1)], btype='band', fs=SAMPLE_RATE)
+        click = _sig.lfilter(bl, al, numpy.pad(click, (0, max(0, n_samples - click_len))))[:click_len].astype(numpy.float32)
+    result = ring + ring2
+    result[:click_len] += click
+    return numpy.tanh(result * 1.8).astype(numpy.float32)
+
+
+def _synth_doumbek_ka(n_samples):
+    """Doumbek Ka — muted edge slap, short and dry."""
+    n = min(n_samples, int(SAMPLE_RATE * 0.04))
+    t = numpy.arange(n, dtype=numpy.float32) / SAMPLE_RATE
+    body = numpy.sin(2 * numpy.pi * 350 * t) * _exp_decay(n, 30) * 0.4
+    slap = _noise(min(80, n)) * _exp_decay(min(80, n), 200) * 0.7
+    result = body
+    result[:min(80, n)] += slap
+    out = numpy.zeros(n_samples, dtype=numpy.float32)
+    out[:n] = numpy.tanh(result * 1.5)
+    return out
+
+
 def _synth_cajon_bass(n_samples):
     """Cajón bass — palm strike on center of the face.
 
@@ -2914,6 +3002,10 @@ def _render_drum_hit(sound_value, n_samples):
         DrumSound.DJEMBE_BASS.value: lambda n: _synth_djembe_bass(n),
         DrumSound.DJEMBE_TONE.value: lambda n: _synth_djembe_tone(n),
         DrumSound.DJEMBE_SLAP.value: lambda n: _synth_djembe_slap(n),
+        # Doumbek
+        DrumSound.DOUMBEK_DUM.value: lambda n: _synth_doumbek_dum(n),
+        DrumSound.DOUMBEK_TEK.value: lambda n: _synth_doumbek_tek(n),
+        DrumSound.DOUMBEK_KA.value: lambda n: _synth_doumbek_ka(n),
         # Cajon
         DrumSound.CAJON_BASS.value: lambda n: _synth_cajon_bass(n),
         DrumSound.CAJON_SLAP.value: lambda n: _synth_cajon_slap(n),
@@ -4510,6 +4602,10 @@ def render_score(score):
         DrumSound.DJEMBE_BASS.value: 0.0,
         DrumSound.DJEMBE_TONE.value: 0.1,
         DrumSound.DJEMBE_SLAP.value: -0.1,
+        # Doumbek
+        DrumSound.DOUMBEK_DUM.value: 0.0,
+        DrumSound.DOUMBEK_TEK.value: 0.1,
+        DrumSound.DOUMBEK_KA.value: -0.1,
         # Cajon — centered (single instrument)
         DrumSound.CAJON_BASS.value: 0.0,
         DrumSound.CAJON_SLAP.value: 0.0,

pytheory/rhythm.py

@@ -213,6 +213,11 @@ INSTRUMENTS = {
         "synth": "steel_drum_synth", "envelope": "none",
         "reverb": 0.3, "reverb_type": "plate",
     },
+    "harmonium": {
+        "synth": "harmonium_synth", "envelope": "organ",
+        "reverb": 0.2, "reverb_type": "taj_mahal",
+        "humanize": 0.15,
+    },
     "accordion": {
         "synth": "accordion_synth", "envelope": "organ",
         "humanize": 0.15,
@@ -383,6 +388,24 @@ class Duration(Enum):
     DOTTED_QUARTER = 1.5
     TRIPLET_QUARTER = 2 / 3
 
+    # Arithmetic — lets you write ``Duration.WHOLE * 2`` → 8.0 beats.
+    def __mul__(self, other):
+        return self.value * other
+
+    def __rmul__(self, other):
+        return self.value * other
+
+    def __truediv__(self, other):
+        return self.value / other
+
+    def __add__(self, other):
+        if isinstance(other, Duration):
+            return self.value + other.value
+        return self.value + other
+
+    def __radd__(self, other):
+        return other + self.value
+
 
 class TimeSignature:
     """A musical time signature like 4/4 or 6/8."""
@@ -528,6 +551,10 @@ class DrumSound(Enum):
     DJEMBE_BASS = 102    # open bass (center of head)
     DJEMBE_TONE = 103    # open tone (edge, fingers together)
     DJEMBE_SLAP = 104    # slap (edge, fingers spread, sharp crack)
+    # Doumbek (darbuka) sounds
+    DOUMBEK_DUM = 112    # center of head, deep bass
+    DOUMBEK_TEK = 113    # edge of head, sharp high
+    DOUMBEK_KA = 114     # muted edge slap
     # Cajon sounds
     CAJON_BASS = 108     # center of face, deep thump
     CAJON_SLAP = 109     # top edge, snare wires buzz
@@ -1563,6 +1590,61 @@ Pattern._PRESETS["tabla solo"] = dict(
     ],
 )
 
+# ── Doumbek patterns ──────────────────────────────────────────────────────
+DKD = DrumSound.DOUMBEK_DUM
+DKT = DrumSound.DOUMBEK_TEK
+DKK = DrumSound.DOUMBEK_KA
+
+# Maqsoum — the most common Arabic rhythm (4/4)
+Pattern._PRESETS["maqsoum"] = dict(
+    name="maqsoum",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(DKD, 0.0, 85), _h(DKT, 0.5, 65),
+        _h(DKT, 1.0, 68), _h(DKD, 1.5, 80),
+        _h(DKT, 2.0, 65), _h(DKT, 2.5, 62),
+        _h(DKT, 3.0, 68), _h(DKT, 3.5, 62),
+    ],
+)
+
+# Baladi — heavy, earthy, belly dance
+Pattern._PRESETS["baladi"] = dict(
+    name="baladi",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(DKD, 0.0, 88), _h(DKD, 0.5, 78),
+        _h(DKT, 1.0, 70), _h(DKD, 1.5, 82),
+        _h(DKT, 2.0, 68), _h(DKT, 2.5, 62),
+        _h(DKT, 3.0, 68), _h(DKK, 3.25, 45), _h(DKT, 3.5, 65),
+    ],
+)
+
+# Saidi — Upper Egyptian, strong and driving
+Pattern._PRESETS["saidi"] = dict(
+    name="saidi",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(DKD, 0.0, 88), _h(DKT, 0.5, 65),
+        _h(DKD, 1.0, 82), _h(DKD, 1.5, 78),
+        _h(DKT, 2.0, 70), _h(DKT, 2.5, 62),
+        _h(DKT, 3.0, 68), _h(DKT, 3.5, 62),
+    ],
+)
+
+# Ayoub — simple 2/4, trance-like repetition
+Pattern._PRESETS["ayoub"] = dict(
+    name="ayoub",
+    time_signature="2/4",
+    beats=2.0,
+    hits=[
+        _h(DKD, 0.0, 85), _h(DKK, 0.5, 45),
+        _h(DKT, 1.0, 70), _h(DKT, 1.5, 62),
+    ],
+)
+
 # ── Cajón patterns ────────────────────────────────────────────────────────
 CB = DrumSound.CAJON_BASS
 CSL = DrumSound.CAJON_SLAP
@@ -2093,6 +2175,226 @@ Pattern._FILLS["second line"] = dict(
     ],
 )
 
+# ── Doumbek fills ────────────────────────────────────────────────────────
+_DKD = DrumSound.DOUMBEK_DUM
+_DKT = DrumSound.DOUMBEK_TEK
+_DKK = DrumSound.DOUMBEK_KA
+
+# Doumbek roll — rapid teks building to dum
+Pattern._FILLS["doumbek roll"] = dict(
+    name="doumbek roll fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        *[_h(_DKT, i * 0.125, 40 + i * 4) for i in range(16)],
+        _h(_DKD, 2.0, 100), _h(_DKT, 2.25, 65), _h(_DKT, 2.5, 68),
+        _h(_DKD, 3.0, 110), _h(_DKD, 3.25, 105),
+        _h(_DKD, 3.5, 115), _h(_DKT, 3.75, 80),
+    ],
+)
+
+# Doumbek accent — syncopated dum-tek-ka pattern
+Pattern._FILLS["doumbek accent"] = dict(
+    name="doumbek accent fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(_DKD, 0.0, 95), _h(_DKT, 0.25, 65), _h(_DKK, 0.5, 50),
+        _h(_DKT, 0.75, 68), _h(_DKD, 1.0, 90),
+        _h(_DKT, 1.5, 72), _h(_DKK, 1.75, 52), _h(_DKD, 2.0, 100),
+        _h(_DKT, 2.25, 68), _h(_DKT, 2.5, 70), _h(_DKT, 2.75, 72),
+        _h(_DKD, 3.0, 110), _h(_DKD, 3.5, 115),
+    ],
+)
+
+# ── Tabla fills ──────────────────────────────────────────────────────────
+_TNA = DrumSound.TABLA_NA
+_TDH = DrumSound.TABLA_DHA
+_TTT = DrumSound.TABLA_TIT
+_TKE = DrumSound.TABLA_KE
+_TGB = DrumSound.TABLA_GE_BEND
+_TGE = DrumSound.TABLA_GE
+_TTI = DrumSound.TABLA_TIN
+_T3 = 1.0 / 12.0
+
+# Tihai — the classic 3x pattern landing on sam
+Pattern._FILLS["tihai"] = dict(
+    name="tihai fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(_TDH, 0.0, 105), _h(_TNA, 0.25, 72), _h(_TTT, 0.5, 48),
+        _h(_TKE, 0.75, 52), _h(_TDH, 1.0, 100),
+        _h(_TDH, 1.25, 110), _h(_TNA, 1.5, 78), _h(_TTT, 1.75, 52),
+        _h(_TKE, 2.0, 55), _h(_TDH, 2.25, 105),
+        _h(_TDH, 2.5, 118), _h(_TNA, 2.75, 82), _h(_TTT, 3.0, 58),
+        _h(_TKE, 3.25, 60), _h(_TDH, 3.5, 127),
+    ],
+)
+
+# Chakkardar — 32nd triplet cascade into slam
+Pattern._FILLS["chakkardar"] = dict(
+    name="chakkardar fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        *[_h(_TTT, i * _T3, 32 + i * 3) for i in range(12)],
+        _h(_TDH, 1.0, 115), _h(_TGB, 1.5, 108),
+        *[_h(_TTT, 2.0 + i * _T3, 35 + i * 3) for i in range(12)],
+        _h(_TDH, 3.0, 120), _h(_TDH, 3.25, 115),
+        _h(_TGB, 3.5, 120), _h(_TDH, 3.75, 127),
+    ],
+)
+
+# Tiri kita fill — rapid 16th note dayan burst
+Pattern._FILLS["tiri kita"] = dict(
+    name="tiri kita fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(_TTT, 0.0, 50), _h(_TTT, 0.125, 38), _h(_TKE, 0.25, 48),
+        _h(_TNA, 0.5, 72), _h(_TTT, 0.75, 42),
+        _h(_TDH, 1.0, 95), _h(_TTT, 1.25, 38), _h(_TTT, 1.5, 42),
+        _h(_TKE, 1.75, 48), _h(_TNA, 2.0, 75),
+        _h(_TTT, 2.25, 40), _h(_TTT, 2.5, 45), _h(_TKE, 2.75, 50),
+        _h(_TDH, 3.0, 100), _h(_TNA, 3.25, 70),
+        _h(_TDH, 3.5, 110), _h(_TGB, 3.75, 105),
+    ],
+)
+
+# Bayan showcase — deep bass bends
+Pattern._FILLS["bayan"] = dict(
+    name="bayan fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(_TGB, 0.0, 100), _h(_TNA, 0.5, 65),
+        _h(_TGE, 1.0, 85), _h(_TGB, 1.5, 105),
+        _h(_TNA, 2.0, 70), _h(_TKE, 2.25, 48),
+        _h(_TGB, 2.5, 110), _h(_TDH, 3.0, 115),
+        _h(_TGB, 3.5, 120),
+    ],
+)
+
+# Call and response — dayan speaks, bayan answers
+Pattern._FILLS["tabla call"] = dict(
+    name="tabla call fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(_TNA, 0.0, 105), _h(_TNA, 0.25, 55), _h(_TTT, 0.5, 38),
+        _h(_TNA, 0.75, 100),
+        _h(_TGE, 1.0, 95), _h(_TGE, 1.25, 48), _h(_TGB, 1.5, 90),
+        _h(_TNA, 2.0, 108), _h(_TTT, 2.125, 30), _h(_TTT, 2.25, 35),
+        _h(_TNA, 2.5, 100),
+        _h(_TGB, 3.0, 112), _h(_TKE, 3.25, 48),
+        _h(_TDH, 3.5, 120),
+    ],
+)
+
+# ── Cajón fills ──────────────────────────────────────────────────────────
+
+# Cajón flam run — slaps accelerating into bass hit
+Pattern._FILLS["cajon flam"] = dict(
+    name="cajon flam fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(CSL, 0.0, 95), _h(CT, 0.125, 45), _h(CSL, 0.25, 90),
+        _h(CB, 0.5, 100), _h(CT, 0.75, 50),
+        _h(CSL, 1.0, 88), _h(CT, 1.125, 42), _h(CSL, 1.25, 92),
+        _h(CT, 1.5, 55), _h(CSL, 1.75, 85),
+        _h(CB, 2.0, 105), _h(CSL, 2.25, 75), _h(CT, 2.5, 48),
+        _h(CSL, 2.75, 80), _h(CT, 2.875, 40),
+        _h(CB, 3.0, 110), _h(CSL, 3.25, 90), _h(CSL, 3.5, 95),
+        _h(CB, 3.75, 120),
+    ],
+)
+
+# Cajón rumble — fast taps building to slap accents
+Pattern._FILLS["cajon rumble"] = dict(
+    name="cajon rumble fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        *[_h(CT, i * 0.125, 35 + i * 3) for i in range(16)],
+        _h(CSL, 2.0, 95), _h(CSL, 2.5, 100),
+        _h(CB, 3.0, 108), _h(CSL, 3.25, 88),
+        _h(CB, 3.5, 112), _h(CSL, 3.75, 95),
+    ],
+)
+
+# Cajón breakdown — syncopated bass-slap groove
+Pattern._FILLS["cajon breakdown"] = dict(
+    name="cajon breakdown fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        _h(CB, 0.0, 100), _h(CT, 0.25, 45), _h(CSL, 0.5, 85),
+        _h(CB, 1.0, 95), _h(CSL, 1.25, 78), _h(CT, 1.5, 50),
+        _h(CSL, 1.75, 82),
+        _h(CB, 2.0, 105), _h(CT, 2.125, 40), _h(CT, 2.25, 42),
+        _h(CSL, 2.5, 90), _h(CT, 2.75, 48),
+        _h(CB, 3.0, 115), _h(CSL, 3.25, 95),
+        _h(CB, 3.5, 110), _h(CSL, 3.75, 100),
+    ],
+)
+
+# ── Metal fills (using metal kit) ────────────────────────────────────────
+
+# Metal triplet — double kick triplets with snare accents
+Pattern._FILLS["metal triplet"] = dict(
+    name="metal triplet fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        # Triplet kick pattern (12 kicks across 4 beats = triplet 8ths)
+        *[_h(MK, i * (1/3), 95 + (i % 3 == 0) * 15) for i in range(12)],
+        # Snare accents on downbeats
+        _h(MS, 0.0, 110), _h(MS, 1.0, 105),
+        _h(MS, 2.0, 110), _h(MS, 3.0, 115),
+        # Hat on upbeats
+        _h(MH, 0.5, 60), _h(MH, 1.5, 60),
+        _h(MH, 2.5, 65), _h(MH, 3.5, 70),
+    ],
+)
+
+# Metal blastbeat variant — alternating snare/kick 32nds
+Pattern._FILLS["metal blast"] = dict(
+    name="metal blast fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        # Alternating kick-snare at 32nd note speed for 2 beats
+        *[_h(MK if i % 2 == 0 else MS, i * 0.125, 100 + i) for i in range(16)],
+        # Then crash into half-time for 2 beats
+        _h(MK, 2.0, 120), _h(MS, 2.5, 115),
+        _h(MK, 3.0, 120), _h(MH, 3.25, 80),
+        _h(MS, 3.5, 120),
+    ],
+)
+
+# Metal cascade — descending snare/kick rolls
+Pattern._FILLS["metal cascade"] = dict(
+    name="metal cascade fill",
+    time_signature="4/4",
+    beats=4.0,
+    hits=[
+        # Fast snare roll beat 1
+        *[_h(MS, i * 0.125, 80 + i * 5) for i in range(8)],
+        # Double kick beat 2
+        *[_h(MK, 1.0 + i * 0.125, 90 + i * 3) for i in range(8)],
+        # Alternating beat 3
+        _h(MS, 2.0, 105), _h(MK, 2.125, 95),
+        _h(MS, 2.25, 108), _h(MK, 2.375, 98),
+        _h(MS, 2.5, 110), _h(MK, 2.625, 100),
+        _h(MS, 2.75, 112), _h(MK, 2.875, 102),
+        # Crash ending
+        _h(MK, 3.0, 120), _h(MS, 3.0, 120),
+        _h(MK, 3.5, 120), _h(MS, 3.5, 120),
+    ],
+)
+
 
 class Part:
     """A named voice within a Score, with its own synth, envelope, and effects.

test_pytheory.py

@@ -4869,6 +4869,19 @@ def test_duration_values():
     assert abs(Duration.TRIPLET_QUARTER.value - 2 / 3) < 1e-9
 
 
+def test_duration_arithmetic():
+    # Multiplication
+    assert Duration.WHOLE * 2 == 8.0
+    assert 2 * Duration.HALF == 4.0
+    assert Duration.QUARTER * 3 == 3.0
+    # Division
+    assert Duration.WHOLE / 2 == 2.0
+    # Addition
+    assert Duration.HALF + Duration.QUARTER == 3.0
+    assert Duration.HALF + 1.0 == 3.0
+    assert 1.0 + Duration.HALF == 3.0
+
+
 def test_time_signature_from_string_4_4():
     ts = TimeSignature.from_string("4/4")
     assert ts.beats == 4
@@ -5320,7 +5333,7 @@ def test_supersaw_wave():
 @needs_portaudio
 def test_all_synths_in_enum():
     from pytheory.play import Synth
-    assert len(Synth) == 41
+    assert len(Synth) == 42
     for s in Synth:
         wave = s(440, n_samples=1000)
         assert len(wave) == 1000
@@ -7142,7 +7155,7 @@ def test_score_system_propagates():
 
 def test_synth_enum_count():
     from pytheory.play import Synth
-    assert len(Synth) == 41
+    assert len(Synth) == 42
 
 
 def test_all_synths_render_and_enum_match():

uv.lock

@@ -698,7 +698,7 @@ wheels = [
 
 [[package]]
 name = "pytheory"
-version = "0.36.3"
+version = "0.36.6"
 source = { editable = "." }
 dependencies = [
     { name = "numeral" },