strudel-guide

Strudel Music Coding Guidelines

Requirements

• Browser with https://strudel.cc/ (no installation needed)
• Copy-paste code, Ctrl+Enter to play, Ctrl+. to stop

Essentials

• Tempo - Set BPM first with setcpm(BPM/4), see references/tempo-timing.md
• Mini-notation - Space-separated sequences, * multiply, / divide, <> alternate, [] subdivide, ~ rest, see references/mini-notation.md
• Layering - Use stack() to combine patterns, each layer independent, see references/layering.md
• Sounds - Drums: bd, sd, hh, oh, cp; Synths: sine, sawtooth, square, triangle, see references/sounds.md
• Effects - .gain(), .lpf(), .room(), .delay(), .shape(), .crush(), see references/effects.md
• Modulation - sine.range(a,b).slow(n) for sweeps, perlin for organic variation, see references/modulation.md
• Conditional - .every(n, fn), .sometimes(fn), .degradeBy(p) for variation, see references/conditionals.md
• Structure - Use .mask() for sections, arrange() for song form, see references/arrangement.md

Example

setcpm(138 / 4);

stack(
  s("bd*4").gain(0.8),
  s("~ cp ~ cp").gain(0.5).room(0.3),
  s("hh*16").gain(0.3).lpf(sine.range(800, 4000).slow(4)),
  note("a2*8").sound("sawtooth").lpf(700).gain(0.5),
  note("<a3 f3 c4 g3>").sound("sawtooth").lpf(2000).room(0.8).gain(0.3),
);

Gotchas

• Pattern transformations are right-associative — s("bd").fast(2).rev() is read right-to-left; the order changes the result
• Time signatures bind to the cycle, not bars — switching cycle length mid-piece shifts everything downstream
• Sample rate of loaded samples affects pitch — uploading 48 kHz samples to a 44.1 kHz session shifts notes by a semitone
• stack adds voices in parallel; cat concatenates in series — confusing them silently doubles or halves the pattern duration

Progressive Disclosure

• Read references/mini-notation.md - Load when learning pattern syntax or fixing notation errors
• Read references/sounds.md - Load when selecting instruments or troubleshooting missing sounds
• Read references/effects.md - Load when applying audio processing or creating textures
• Read references/modulation.md - Load when adding movement and dynamic variation
• Read references/conditionals.md - Load when creating algorithmic variation
• Read references/layering.md - Load when combining multiple patterns
• Read references/tempo-timing.md - Load when setting tempo or working with time
• Read references/arrangement.md - Load when structuring full compositions
• Read references/genre-trance.md - Load when producing uplifting/hard trance
• Read references/genre-ambient.md - Load when creating atmospheric soundscapes
• Read references/genre-harsh.md - Load when making experimental/industrial music
• Read references/scales-harmony.md - Load when working with melodies and chords