Strudel Reference

Quick reference for Strudel syntax. Not exhaustive - experiment and discover.

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The Basics

Everything happens in cycles (≈2 seconds by default).

$: s("bd")           // One kick per cycle
$: s("bd*4")         // Four kicks per cycle
$: s("bd sd bd sd")  // Sequence: kick-snare-kick-snare
$: s("bd*4, hh*8")   // Layers: kick AND hats together

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Mini-Notation Cheatsheet

Symbol	Meaning	Example
*n	Repeat n times	hh*4
/n	Slow down n times	[c d e f]/2
[ ]	Group (subdivide)	[bd sd] hh
< >	Alternate each cycle	<bd sd cp>
,	Play in parallel (stack)	bd, hh*2
~ or -	Rest (silence)	bd ~ sd ~
?	50% chance to play	hh*8?
(n,m)	Euclidean rhythm	bd(3,8)
@n	Elongate (weight)	c@3 e
!n	Replicate	bd!3 sd
|	Random choice	bd | sd | cp
:n	Sample number	hh:2

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Sounds

Basic Drums: bd sd hh cp oh rim lt mt ht cr rd cb

Drum Banks (classic): .bank("RolandTR909") .bank("RolandTR808") .bank("RolandTR707")

Drum Machines Catalog

Use with sample pattern: s("tr808_bd tr808_sd tr808_hh") or with :n for variations: s("tr808_bd:0 tr808_bd:5")

ROLAND (The Classics)

Machine	Sound	Vibe
tr808	25 kicks, 25 snares, 5 toms each	THE hip-hop/electro sound
tr909	4 kicks, 16 snares, 9 toms each	THE house/techno sound
tr707	2 kicks, 2 snares	Clean 80s digital
tr606	1 each	Acid house companion
tr626	2 kicks, 3 snares, 8 percs	Latin percussion
tr505	1 each, 3 percs	Budget 80s
tr727	10 percs, 2 shakers	Latin percussion only
mc303	16 kicks, 26 snares, 39 percs	Groovebox monster
r8	7 kicks, 12 snares, 8 percs	Pro 90s workstation
d110	3 snares, 3 percs	LA Synthesis module
d70	4 kicks, 5 snares	90s workstation
system100	15 kicks, 21 snares, 19 percs	Modular analog
sh09	43 kicks	Synth bass drums

LINN (The Originals)

Machine	Sound	Vibe
linndrum	1 kick, 3 snares, 3 hats, 6 percs	Prince, 80s pop legend
lm1 / linnlm1	4 kicks, 1 snare, 3 percs	First real drum machine
lm2 / linnlm2	4 kicks, 4 snares	LM-1 successor
linn9000 / 9000	2 crashes, 2 toms each, 3 percs	Sampling pioneer
linn / akailinn	Full kit	Akai recreation

OBERHEIM

Machine	Sound	Vibe
dmx / oberheimdmx	3 kicks, 3 snares	New Order, early hip-hop

E-MU

Machine	Sound	Vibe
sp12 / emusp12	14 kicks, 21 snares, 6 toms each	Sampling legend
drumulator / emudrumulator	1 each	Budget classic
emumodular	2 kicks, 2 percs	Modular weirdness

YAMAHA

Machine	Sound	Vibe
rm50 / yamaharm50	103 kicks, 108 snares, 56 percs	MASSIVE library
ry30 / yamahary30	13 kicks, 21 snares, 13 percs	AWM synthesis
rx5 / yamaharx5	2 kicks, 3 snares, FX	FM drums
rx21 / yamaharx21	1 each	Budget FM
tg33 / yamahatg33	4 kicks, 5 snares, 12 percs	Vector synthesis

KORG

Machine	Sound	Vibe
m1 / korgm1	3 kicks, 4 snares, 16 misc, 7 percs	Workstation king
minipops / korgminipops	7 kicks, 13 snares	Vintage analog
kpr77 / korgkpr77	1 each	Preset rhythm
kr55 / korgkr55	1 each, 2 percs	Analog preset
ddm110 / korgddm110	1 kick, 2 toms each	Digital
poly800 / korgpoly800	4 kicks	Synth kicks
t3 / korgt3	5 kicks, 5 snares, 4 percs	Workstation
krz / korgkrz	2 snares, 2 FX	Trinity/Triton

BOSS

Machine	Sound	Vibe
dr110 / bossdr110	1 each	Compact analog
dr220 / bossdr220	Full kit + perc	Digital 80s
dr55 / bossdr55	2 kicks, 8 snares, 2 hats	Dr. Rhythm
dr550 / bossdr550	5 kicks, 6 snares, 11 percs	Pro 90s

ALESIS

Machine	Sound	Vibe
hr16 / alesishr16	1 each, 8 percs, 3 shakers	80s digital
sr16 / alesissr16	13 kicks, 12 snares, 7 percs	Studio staple

SEQUENTIAL CIRCUITS

Machine	Sound	Vibe
circuitsdrumtracks	1 each	Early digital
circuitstom	2 hi toms	Tom module

AKAI

Machine	Sound	Vibe
mpc60 / akaimpc60	2 kicks, 3 snares, 5 percs	Hip-hop legend
mpc1000	5 kicks, 4 snares	Modern MPC
xr10 / akaixr10	10 kicks, 10 snares, 15 percs	XR series

CASIO

Machine	Sound	Vibe
rz1 / casiorz1	1 each, 2 rides	Sampling keyboard
sk1 / casiosk1	1 each	Toy sampling
vl1 / casiovl1	1 each	VL-Tone

SIMMONS

Machine	Sound	Vibe
sds5 / simmonssds5	12 kicks, 21 snares, 7 rims	Electronic drum pads
sds400 / simmonssds400	3 snares, 8 mid toms, 6 lo toms	Tom heaven

OTHER GEMS

Machine	Sound	Vibe
spacedrum / viscospacedrum	11 kicks, 6 hats, 7 hi toms	Weird analog
dpm48 / sakatadpm48	3 kicks, 2 snares, 2 percs	Sakata
compurhythm78	8 percs, 4 misc	Roland CR-78
compurhythm1000	Full kit, 3 percs	Roland CR-1000
compurhythm8000	Full kit, 2 percs	Roland CR-8000
mfb512	1 each	German analog
sergemodular	5 percs	Serge modular
mridangam_*	South Indian percussion	dhi, dhin, ka, ta, thom, etc.

Sample Counts Key: Numbers in parentheses indicate variations available via :n

// Classic 808 kit
s("tr808_bd tr808_sd:3 tr808_hh*2 tr808_oh").gain(0.8)

// Mix machines for unique kits
s("tr909_bd linndrum_sd tr808_hh dmx_cp")

// Explore variations
s("tr808_bd:<0 5 10 15 20>") // cycle through 808 kick variations

// Lo-fi with SP-12
s("sp12_bd sp12_sd:5 sp12_hh").lpf(2000).room(0.4)

// Yamaha RM50 has EVERYTHING
s("rm50_bd:50 rm50_sd:30 rm50_perc:20")

Synthesizers

Basic Waveforms:

Sound	Alias	Description
sine	sin	Pure tone, smooth
triangle	tri	Soft, flute-like
sawtooth	saw	Bright, buzzy - classic synth
square	sqr	Hollow, clarinet-like
supersaw	-	Detuned saws - huge pads
pulse	-	Variable width square

Noise Sources:

Sound	Character
white	Full spectrum hiss
pink	Warmer, less harsh
brown	Deep rumble

Z-Oscillators (aliased/lo-fi): z_sine z_sawtooth z_square z_triangle z_tan z_noise

Other Synths:

Sound	Description
zzfx	ZzFX game audio synth
bytebeat	Algorithmic 8-bit
crackle	Vinyl crackle noise

Wavetables

// Wavetable synthesis
s("wt_digital:2").note("c3 e3 g3 c4")

Wavetable	Variations	Vibe
wt_digital	5	Digital textures
wt_digital_bad_day	1	Moody digital
wt_digital_basique	1	Simple digital
wt_digital_crickets	1	Insect-like
wt_digital_curses	1	Harsh digital
wt_digital_echoes	1	Spacey
wt_vgame	11	Video game sounds

GM Instruments (General MIDI)

All have multiple velocity layers (number in parentheses). Use :n for variations.

Pianos (Keys):

Sound	Layers	Character
gm_piano	32	Acoustic grand
gm_epiano1	11	Rhodes-style
gm_epiano2	9	DX7-style
gm_harpsichord	8	Baroque
gm_clavinet	4	Funky

Chromatic Percussion:

Sound	Layers
gm_celesta	6
gm_glockenspiel	5
gm_music_box	5
gm_vibraphone	6
gm_marimba	7
gm_xylophone	6
gm_tubular_bells	6
gm_dulcimer	5

Organs: gm_drawbar_organ gm_percussive_organ gm_rock_organ gm_church_organ gm_reed_organ gm_accordion gm_harmonica gm_bandoneon

Guitars: gm_acoustic_guitar_nylon gm_acoustic_guitar_steel gm_electric_guitar_jazz gm_electric_guitar_clean gm_electric_guitar_muted gm_overdriven_guitar gm_distortion_guitar gm_guitar_harmonics

Bass: gm_acoustic_bass gm_electric_bass_finger gm_electric_bass_pick gm_fretless_bass gm_slap_bass_1 gm_slap_bass_2 gm_synth_bass_1 gm_synth_bass_2

Strings: gm_violin gm_viola gm_cello gm_contrabass gm_tremolo_strings gm_pizzicato_strings gm_orchestral_harp gm_timpani

Ensemble: gm_string_ensemble_1 gm_string_ensemble_2 gm_synth_strings_1 gm_synth_strings_2 gm_choir_aahs gm_voice_oohs gm_synth_choir gm_orchestra_hit

Brass: gm_trumpet gm_trombone gm_tuba gm_muted_trumpet gm_french_horn gm_brass_section gm_synth_brass_1 gm_synth_brass_2

Reeds: gm_soprano_sax gm_alto_sax gm_tenor_sax gm_baritone_sax gm_oboe gm_english_horn gm_bassoon gm_clarinet

Pipes: gm_piccolo gm_flute gm_recorder gm_pan_flute gm_blown_bottle gm_shakuhachi gm_whistle gm_ocarina

Synth Leads: gm_lead_1_square gm_lead_2_sawtooth gm_lead_3_calliope gm_lead_4_chiff gm_lead_5_charang gm_lead_6_voice gm_lead_7_fifths gm_lead_8_bass_lead

Synth Pads: gm_pad_new_age gm_pad_warm gm_pad_poly gm_pad_choir gm_pad_bowed gm_pad_metallic gm_pad_halo gm_pad_sweep

Synth FX: gm_fx_rain gm_fx_soundtrack gm_fx_crystal gm_fx_atmosphere gm_fx_brightness gm_fx_goblins gm_fx_echoes gm_fx_sci_fi

Ethnic: gm_sitar gm_banjo gm_shamisen gm_koto gm_kalimba gm_bagpipe gm_fiddle gm_shanai

Percussive: gm_tinkle_bell gm_agogo gm_steel_drums gm_woodblock gm_taiko_drum gm_melodic_tom gm_synth_drum gm_reverse_cymbal

Sound FX: gm_guitar_fret_noise gm_breath_noise gm_seashore gm_bird_tweet gm_telephone gm_helicopter gm_applause gm_gunshot

// Switch between sounds (space = alternate)
note("c d e f").sound("piano gm_electric_guitar_muted")

// Stack sounds (comma = layer together)
note("c d e f").sound("piano, gm_electric_guitar_muted")

// FM Synthesis
.fm(4)            // FM modulation index
.fmh(2)           // FM harmonicity ratio

// Vibrato
.vib(4)           // Vibrato speed (hz)
.vibmod(0.5)      // Vibrato depth (semitones)

Samples Catalog

High-quality multi-sampled instruments. Numbers show available variations.

Pianos & Keys:

Sample	Variations	Character
piano	29	Acoustic grand
piano1	22	Alternative piano
steinway	42	Concert grand
fmpiano	22	FM synthesis piano
kawai	37	Kawai grand
clavisynth	19	Clavinet-style synth

Strings & Harps:

Sample	Variations
folkharp	29
harp	23
psaltery_bow	11
psaltery_pluck	11
psaltery_spiccato	11
strumstick	19

Mallet Instruments:

Sample	Variations	Character
kalimba	11	Thumb piano
kalimba2 - kalimba5	14-25	More kalimbas
marimba	10	Wooden bars
glockenspiel	7	Metal bells
vibraphone	11	Jazz vibes
vibraphone_bowed	6	Bowed vibes
vibraphone_soft	11	Soft mallets
xylophone_hard_ff	8	Hard mallets loud
xylophone_soft_pp	8	Soft mallets quiet
balafon	6	African xylophone
balafon_hard / _soft	6	Articulation variants
tubularbells	9	Orchestral chimes
tubularbells2	11	Alternative
handbells	3	Hand bells
handchimes	19	Wind chimes
belltree	6	Bell tree
wineglass	4	Rubbed glass

Wind Instruments:

Sample	Variations
recorder_soprano_sus	13
recorder_soprano_stacc	12
recorder_alto_sus	12
recorder_alto_vib	12
recorder_tenor_sus	13
recorder_bass_sus	12
ocarina	11
ocarina_small	10
ocarina_vib	10
harmonica	9
harmonica_soft	10
harmonica_vib	10
sax	23
sax_stacc	23
sax_vib	19
saxello	8
super64	13 (chromatic harmonica)

Organs:

Sample	Variations
organ_4inch	27
organ_8inch	27
organ_full	27
pipeorgan_loud	21
pipeorgan_quiet	21
pipeorgan_loud_pedal	11
pipeorgan_quiet_pedal	11

Percussion - Pitched:

Sample	Variations
timpani	30
timpani_roll	10
timpani2	204 (!)
slitdrum	6

Percussion - Drums:

Sample	Variations
bassdrum1	8
bassdrum2	30
snare_hi	8
snare_low	20
snare_modern	72
snare_rim	4
tom_stick	8
tom_mallet	8
tom_rim	6
tom2_stick / mallet / rim	6-8
hihat	15
clap	10
jazz	8 (jazz kit)

Percussion - World:

Sample	Variations	Origin
bongo	28	Latin
conga	34	Latin
cajon	18	Flamenco
darbuka	20	Middle Eastern
framedrum	18	World
tambourine	7	Universal
tambourine2	7	Alternative
agogo	5	Brazilian
shaker_large	6	Universal
shaker_small	16	Universal
cabasa	6	Latin
cowbell	13	Universal
clave	6	Latin
guiro	5	Latin

Percussion - Metals:

Sample	Variations
sus_cymbal	25
sus_cymbal2	23
clash	10
clash2	5
triangles	37
fingercymbal	1
gong	7
gong2	6
sleighbells	6
anvil	9
metal	10
brakedrum	17

Percussion - Wood & Effects:

Sample	Variations
woodblock	10
marktrees	6
ratchet	8
slapstick	5
vibraslap	4
flexatone	8
oceandrum	3

Asian Instruments:

Sample	Variations	Origin
dantranh	17	Vietnamese zither
dantranh_tremolo	16	With tremolo
dantranh_vibrato	16	With vibrato
didgeridoo	12	Australian

Sound Effects:

Sample	Variations
space	18
siren	5
trainwhistle	6
ballwhistle	2
wind	10
crow	4
insect	3
casio	3
east	9
num	21
numbers	9

// Multi-sampled piano
s("steinway").note("c3 e3 g3 c4")

// World percussion
s("conga:5 conga:12 bongo:3 bongo:8").gain(0.7)

// Vietnamese zither with tremolo
s("dantranh_tremolo:8").note("c4 e4 g4")

// Mix sample types
s("timpani:5, sus_cymbal:10").note("c2")

---

Notes

note("c4 e4 g4")                 // Letter notation
n("0 2 4 7").scale("C:minor")    // Scale degrees
chord("<Cm7 Fm7>").voicing()     // Chords

---

Scales

Use n() with .scale() - any number will sound good in the scale.

Common scales:

• C:major - happy, bright
• A:minor - sad, emotional
• D:dorian - jazzy, soulful
• G:mixolydian - bluesy, groovy
• A:minor:pentatonic - safe, universal
• F:major:pentatonic - bright, easy

With octave: A2:minor (starts at A2)

Automate scales:

n("0 2 4 7").scale("<C:major D:mixolydian>/4")

---

Sampler Controls

.speed(2)         // Playback speed (negative = reverse)
.begin(0.25)      // Start point (0-1)
.end(0.75)        // End point (0-1)
.clip(0.5)        // Duration multiplier
.cut(1)           // Cut group (stops others in same group)
.loopAt(4)        // Fit sample to n cycles
.fit()            // Fit sample to event duration

// Slicing
.chop(8)          // Chop into n pieces
.slice(8, "0 1 2 3 4 5 6 7")  // Slice and reorder
.splice(8, "0 1 2 3")         // Like slice, speed-adjusted

---

Envelopes

// Amplitude ADSR
.attack(0.1)      // Attack time (seconds)
.decay(0.2)       // Decay time
.sustain(0.5)     // Sustain level (0-1)
.release(0.3)     // Release time

// Filter envelope (add to lpf)
.lpenv(4)         // Envelope depth
.lpa(0.1)         // Filter attack
.lpd(0.2)         // Filter decay

// Pitch envelope
.penv(12)         // Pitch envelope depth (semitones)

---

Effects

// Filters
.lpf(800)         // Low-pass filter
.hpf(200)         // High-pass filter
.lpq(10)          // Resonance
.vowel("a e i o") // Vowel filter

// Space
.room(0.5)        // Reverb amount
.size(4)          // Reverb size
.delay(0.5)       // Delay amount
.delaytime(0.25)  // Delay time
.delayfb(0.5)     // Delay feedback

// Dynamics
.gain(0.8)        // Volume
.pan(0.5)         // Stereo position
.distort(0.2)     // Distortion
.shape(0.3)       // Waveshaping
.crush(4)         // Bit crush

---

Signals (Continuous Patterns)

// Waveforms (0-1)
sine              // Smooth oscillation
saw               // Ramp up
tri               // Triangle
square            // Square wave
cosine            // Cosine

// Random
rand              // Random 0-1
perlin            // Smooth random
irand(8)          // Random integer 0-7

// Modifiers
.range(200, 2000) // Scale to range
.slow(8)          // Slow the signal

// Example: filter sweep
.lpf(sine.range(200, 2000).slow(8))

---

Pattern Functions

// Time
.fast(2)          // Double speed
.slow(2)          // Half speed
.early(0.25)      // Shift earlier
.late(0.25)       // Shift later

// Structure
.rev()            // Reverse
.palindrome()     // Forward then backward
.iter(4)          // Shift start each cycle
.ply(2)           // Repeat each event

// Layering
.off(1/8, x=>x.add(7))    // Offset copy + transform
.layer(x=>x.add(7))       // Layer with transform
.superimpose(rev)         // Add reversed copy
.jux(rev)                 // Stereo: L=normal, R=reversed

// Conditional
.every(4, fast(2))        // Every nth cycle
.sometimes(rev)           // 50% chance
.often(fast(2))           // 75% chance
.rarely(rev)              // 25% chance
.struct("x ~ x ~")        // Apply rhythmic structure
.mask("1 0 1 1")          // Silence where 0

// Randomness
.degrade()                // Remove 50% randomly
.degradeBy(0.3)           // Remove 30% randomly
choose("bd", "sd", "cp")  // Pick one randomly

---

Tempo & Duration

setcpm(130/4)     // 130 BPM (4/4 time)
setcpm(180/3)     // 180 BPM waltz (3/4 time)
setcps(0.5)       // 0.5 cycles per second (= 120 BPM)

Duration Math

cps = BPM / 60 / 4
cycles = minutes × 60 × cps

Duration	90 BPM	110 BPM	120 BPM	128 BPM	140 BPM	160 BPM	174 BPM
cps	0.375	0.458	0.5	0.533	0.583	0.667	0.725
2 min	45	55	60	64	70	80	87
5 min	112	137	150	160	175	200	217
10 min	225	275	300	320	350	400	435

Sum your arrange() entries to hit the target.

---

Chord Voicing & Progressions

// Define a progression (angle brackets = one chord per cycle)
let prog = "<Cm7 Fm7 Abmaj7 G7>"

// Basic chord with voicing
chord(prog).voicing().s("piano")

// .anchor() sets the root octave for voicings
chord(prog).anchor("C3").voicing()     // Bass register
chord(prog).anchor("C5").voicing()     // High register

// Dynamic anchors (changes over time)
chord(prog).anchor("<C3@8 C4@4>").voicing()

// .ply(n) repeats each chord n times per cycle
// Great for waltz (3) or house (4) feels
chord(prog).ply(3).gain("0.8 0.3 0.4")  // Waltz: strong-weak-weak
chord(prog).ply(4).gain("1 0.5 0.7 0.5") // House groove

// .arp() arpeggiate through chord tones by index
chord(prog).voicing().arp("0 1 2 3")     // Root, 2nd, 3rd, 4th
chord(prog).voicing().arp("0 2 4 7")     // Wider intervals
chord(prog).ply(6).voicing().arp("0 1 2 3 5 7").rev()  // Descending

// Add octave jumps to arpeggios
chord(prog).voicing().arp("0 1 2 3".add("[12 |0|0]*4"))

// Extract just the root for bass
chord(prog).anchor("C2").voicing().arp("0")

---

Sidechain Ducking

// Make elements duck (lower volume) when another orbit plays
.duckorbit(1)      // Duck when orbit 1 plays
.duckdepth(0.3)    // How much to duck (0-1)

// Classic house sidechain: chords pump with kick
let kick = s("bd").orbit(1)
let chords = chord("<Cm7 Fm7>").voicing()
  .duckorbit(1).duckdepth(0.4)
  .s("piano")

stack(kick, chords)

---

Timeline Arrangements

When user asks to "arrange", "create a track", "make a song", or specifies a duration → use arrange().

arrange(
  [4, intro],
  [8, build],
  [8, drop],
  [4, outro],
)

See /arrange skill for full reference with duration math and genre examples.

---

Probabilistic Variations

// .sometimesBy(probability, transform)
.sometimesBy(0.3, x => x.crush(4))   // 30% chance bitcrush
.sometimesBy(0.5, x => x.rev())      // 50% chance reverse

// Create variation helper functions
const degrade = (x, freq = 0.5) => x
  .sometimesBy(freq, x => x.clip("0.5|0.75"))
  .sometimesBy(freq, x => x.ply("2|3"))

// Use in arrangements
arrange(
  [8, degrade(arpeggio)],
  [8, degrade(arpeggio, 0.25)],  // Less degradation
)

---

Transposition

.trans(12)    // Up one octave (12 semitones)
.trans(-5)    // Down a fourth
.trans(3)     // Up a minor third (key change!)

// Dramatic ending: transpose up
arrange(
  [8, melody],
  [8, melody.trans(3)],  // Key change!
  [4, melody.trans(3).room(1)],
)

---

Genre → Instrument Guide

Genre	Drums	Bass	Keys/Pads	Lead/Melody
House	tr909	sawtooth	gm_pad_warm, gm_epiano1	supersaw
Techno	tr808, tr909	sawtooth, square	gm_pad_metallic	gm_lead_2_sawtooth
Jazz	tr707 (brushes)	gm_acoustic_bass	gm_epiano1, piano	gm_tenor_sax, gm_trumpet
Ambient	minimal/none	gm_contrabass	gm_pad_warm, gm_pad_halo	kalimba, gm_flute
Metal	tr909 (fast)	gm_distortion_guitar	gm_overdriven_guitar	gm_guitar_harmonics
Synthwave	tr808	sawtooth, gm_synth_bass_1	gm_pad_warm	supersaw, gm_lead_2_sawtooth
Lo-fi	vinyl drums	gm_acoustic_bass	gm_epiano1, piano	gm_vibraphone, kalimba
Orchestral	gm_timpani	gm_contrabass, gm_bassoon	gm_string_ensemble_1	gm_violin, gm_flute, gm_french_horn
Latin	congas, bongos	gm_acoustic_bass	piano	gm_trumpet, gm_alto_sax
Funk	tr808	gm_slap_bass_1	gm_clavinet, gm_epiano1	gm_trumpet, gm_tenor_sax

---

Method Syntax (IMPORTANT)

All methods need parentheses. Even methods with no arguments.

// ✅ CORRECT
.rev()
.palindrome()
.degrade()

// ❌ WRONG - will cause errors
.rev
.palindrome
.degrade

Higher-Order Functions

Functions like jux, sometimes, every, off take a function as argument, not a method reference.

// ✅ CORRECT - arrow function
.jux(x => x.rev())
.sometimes(x => x.speed(-1))
.every(4, x => x.fast(2))
.off(0.125, x => x.add(7))

// ❌ WRONG - won't work
.jux(rev)
.sometimes(speed(-1))
.every(4, fast(2))

Chaining After Higher-Order Functions