Mini-notation, one step at a time

Writing one event per pattern gets old fast. note(), sound(), n(), chord(), and s() all accept a mini-notation string that describes a whole cycle of events. Here's the syntax, in the order it's worth learning; the examples use .loop() so you can hear the cycle repeat — call handle.stop() when you've heard enough.

Sequence. Space-separated steps divide the cycle equally. Four steps at the default 120 bpm (a 2-second cycle) means one note every half second:

const handle = note('c4 e4 g4 b4').sound('triangle').loop({ bpm: 120 });

Rests. ~ is a step of silence, taking up its share of the cycle like any other step:

note('c4 ~ e4 ~').sound('triangle').loop({ bpm: 120 });

Subdivision. Square brackets nest a sequence inside one step — the bracketed group splits its parent step's time, so rhythms subdivide naturally:

note('c4 [e4 g4] c4 [e4 g4 b4]').sound('triangle').loop({ bpm: 120 });

Alternation. Angle brackets play a different child each cycle — <b3 c4> is b3 on the first pass, c4 on the next, and so on. This is the cheapest way to make a short pattern feel longer than one cycle:

note('c3 e3 g3 <b3 c4>').sound('triangle').loop({ bpm: 140 });

One nuance worth knowing early: .play() plays cycle zero only, so an alternation in a one-shot always plays its first option. Alternation is a looping construct.

Chords and layers. A comma means "at the same time" — inside brackets it's a chord; at the top level it layers independent sequences (a polyrhythm, since each side divides the cycle its own way):

note('<[c3,e3,g3] [a2,c3,e3] [f2,a2,c3] [g2,b2,d3]>').sound('sine').sustain(0.8).loop({ bpm: 80 });
note('[c4 e4 g4, c2 f2]').sound('triangle').loop({ bpm: 110 }); // 3 against 2

Speed, replication, elongation. a*2 squeezes two repeats of a step into its slot, a/2 stretches it over two cycles, a!3 writes the step three times, and a@3 gives it three shares of the cycle instead of one:

note('c4@3 g4').sound('triangle').loop({ bpm: 120 }); // long c, short g

Euclidean rhythms. a(3,8) distributes 3 onsets as evenly as possible over 8 slots (the tresillo x..x..x.); a third argument rotates the result. Layered euclideans with different pulse counts are an instant groove:

note('[c2(3,8), g2(5,8,2), c4(7,16,4)]').sound('square').sustain(0.12).lpf(900).loop({ bpm: 130 });

Everything composes: <c5 e5 g5 b5 a5 g5>*2 ~ alternates and doubles and rests, and the same string syntax works inside n(), chord(), s(), and — see patterned parameters — every numeric control.