Melody and harmony

Writing every pitch out as note names works, but scale degrees and chord symbols are usually what you're actually thinking in. Both are patterns like everything else, so they mix freely with note() in a stack().

Scale degrees. n() takes integers (or a mini-notation string of them) and .scale('D5:minor') resolves them against a named scale — root note + octave, colon, scale name (major, minor, dorian, mixolydian, harmonicMinor, majorPentatonic, and friends — Pattern.scale() has the full list). Degrees past the scale's length wrap up an octave (7 in a 7-note scale is the root an octave up), and negative degrees descend the same way, so runs and octave jumps are just arithmetic:

import { n } from '@liminal-hq/undertone';

n('0 2 4 <7 -3>').scale('d5:minor').sound('triangle').sustain(0.3).loop({ bpm: 130 });

Chord symbols. chord() takes symbols like Dm9, BbM7, A7sus and .voicing() expands each one into simultaneous pitched notes, exactly as if you'd written a [d3,f3,a3,c4,e4] chord in mini-notation. Voicing is deterministic and anchored around middle C by default (.voicing({ anchor: 'g4' }) to taste), and same-root changes share common tones so progressions don't leap around. Case matters in qualities: M7 is a major seventh, m7 a minor seventh — see chord() for the supported vocabulary.

Putting them together. Since already-pitched events pass through .scale() and .voicing() untouched, a progression, a bassline, and a melody are three patterns stacked:

import { chord, n, note, stack } from '@liminal-hq/undertone';

const progression = chord('<Dm9 BbM7 Gm9 A7sus>').voicing().sound('sine').sustain(0.8).gain(0.35);

const bass = note('<d2 bb1 g1 a1>(3,8)').sound('square').sustain(0.2).lpf(500).gain(0.5);

const melody = n('<0 2 4 5 4 2 1 0>*2 ~')
  .scale('d5:minor')
  .sound('triangle')
  .sustain(0.25)
  .gain(0.3);

const handle = stack(progression, bass, melody).loop({ bpm: 96 });

The alternations line up because they all cycle at the same rate: each cycle gets one chord, the matching bass root, and the next two melody degrees.