Sync to tempo and key

Your device can read where the song is, and what key it's in, from inside process.

The beat

const bpm = ctx.tempo(); // BPM
const playing = ctx.isPlaying();
const bar = ctx.bar();
const beat = ctx.beat();
const phase = ctx.beatPhase(); // 0..1 through the current beat

Drive anything rhythmic with these: flash a light on each beat, step a sequencer. The building blocks also have tempo-sync helpers so an LFO or delay can lock to note values.

The key

For scale-aware tools (a smart arp, a quantizer):

const root = ctx.meshKey(); // 0..11, C = 0
const mask = ctx.meshScaleMask(); // which notes are in scale
const inScale = ctx.noteInScale(note, mask);

Snap a note onto the scale with foldToMask(note, mask) (or foldToScale(note, root, scaleId) for a fixed scale). Full list in Harmony and sequencing.