1one note

bpm 120
lead sin c4

a line is a channel. `lead` is its name. `sin` is the waveform. `c4` is middle C. you'll hear it pulse once per beat.

2a melody

bpm 120
lead sin c4 e4 g4 c5

each token is one step (an 8th note). four tokens = four pitches. the pattern loops forever.

3rests

bpm 120
lead sin c4 . . e4 . . g4 .

`.` is a rest. so is `_` if you prefer. rest tokens count as steps too — this pattern is 8 steps long, not 3.

4a second channel

bpm 120
lead sin c4 e4 g4 c5
bass saw c2 . g2 .

two lines, two channels. they play at the same time. waveforms: `sin`, `tri`, `sqr`, `saw`, `noise`. octaves run 0–8.

5effects

bpm 120
lead sin c4 e4 g4 c5 : vol .5
bass saw c2 . g2 .   : lpf 400

after `:` you can set effects. `vol` (0–1), `lpf` (low-pass filter Hz), `hpf` (high-pass), `decay` (seconds — makes notes percussive). `.5` is shorthand for `0.5`; `400` is just a number; `2k` means 2000.

6drums

bpm 120
kick noise x . . . x . . . : lpf 50 decay .05
hat  noise . . x . . . x . : hpf 8k decay .015

`noise` is the noise waveform. `x` triggers a hit. high-pass + short decay = hi-hat. low-pass + slightly-longer decay = kick.

7multi-line patterns

bpm 96
lead tri
  c4 e4 g4 c5
  g4 e4 c4 .
  : vol .4

indent any line to continue the previous channel. the pattern above plays as `c4 e4 g4 c5 g4 e4 c4 .` — one 8-step loop. effects can live on their own line too.

8expressivity per note

three modifiers attach to any token: `*N` (hold for N steps), `!` (accent), `?` (ghost note).

bpm 120
lead sin c4*4 e4 g4 c5

`c4*4` = trigger c4, sustain across 4 step slots without retriggering. the pattern is 7 steps total: 4 for the held c4, then e4, g4, c5.

bpm 120
lead sin c4! c4 c4? c4

four c4s at four dynamics. `c4!` is louder, `c4?` is quieter, bare `c4` sits in the middle.

modifiers stack. `c4!*4` and `c4*4!` both = an accented note held for four steps. accent + ghost on the same token is an error.

modifiers also work on rests (`.*4` = four rests, useful shorthand) and triggers (`x!` = accented hit; `x*4` = sustained noise).

9chords

bpm 96
pad sin [c4 e4 g4] . [d4 f4 a4] . : vol .4

square brackets pack multiple notes into one step. the channel plays them all at once, so one line can carry harmony without burning a second channel. modifiers attach outside the brackets — `[c4 e4 g4]*4` holds the chord across 4 slots, `[c4 e4 g4]!` accents it.

chords are pitched-only (no `[...]` on a `noise` channel) and cap at 8 notes each. single-note brackets `[c4]` just behave like a plain note.

10polyrhythm — the trick

bpm 120
lead sin c4 e4 g4 c5 e4 g4 c5
kick noise x . . . x . . .

the lead has 7 steps, the kick has 8. they loop independently and never re-align. give two channels different lengths and you get polyrhythm for free. coprime lengths (5 vs 7, 7 vs 11) drift forever.

11live coding

playback runs while you type. edits land after a 300 ms pause:

• pattern changes (note swaps, rests added) take effect on the next scheduler tick.
• structural changes (new channel, swapped waveform, removed channel) quantize to the next step boundary so they land musically.
• press **Cmd/Ctrl+Enter** to apply immediately without waiting on the debounce.
• press **Esc** to stop. press it again with **Cmd/Ctrl+Enter** to start fresh. there is no rewind — start always means step 0.

(this page plays examples read-only — open the app to edit and hear changes live.)

12all together

a full mini-song using everything above:

bpm 96

-- glass
lead tri
  . . f#4 . a4 . c#5 .
  d5 . . . c#5 . a4 .
  : vol .5

bass saw
  d2 . . d2 . . d3 .
  : lpf 200

kick noise x . . . . . x . : lpf 50 decay .06
hat  noise . . x . . . x . : hpf 8k decay .03

four channels, two waveforms, two filters, one decay. a verse loop in fourteen lines.

what to try next

• open one of the demos via the **presets** picker and read it. they're the same `.hum` text you've been writing.
• give two melodic channels different lengths (e.g. 7 vs 11) and listen to them drift. this is hum's core pleasure.
• aim a long `decay` (`.5`, `1.5`) at a `sin` channel — it becomes a pluck or a bell.
• save your song with the **save** button, drag the file onto the page later to load it. `.hum` files are plain text — open them in any editor.

that's the whole language. the [SPEC](SPEC.md) is the full reference; the [demos/](demos/) folder has ten longer examples to read.