Prosody — Quick Reference

Instruments

Prefix any line with an instrument name. Default is piano if omitted.

Pitched

Prefix	Sound	Notes
`piano:`	Sampled piano	Polyphonic, range A0–C8
`synth:`	Fat sawtooth	Polyphonic
`bass:`	Filtered sawtooth	Monophonic
`strings:`	Bowed strings	Polyphonic, slow attack
`pad:`	Ambient pad	Polyphonic, very slow attack
`pluck:`	Plucked string	Polyphonic, instant attack, decays away
`organ:`	Square wave organ	Polyphonic, instant start/stop
`lead:`	Lead synth	Monophonic, bright filter
`bell:`	Bell / glockenspiel	Polyphonic, long decay

Percussion

Prefix	Sound	Trigger
`kick:`	Kick drum	`x`
`snare:`	Snare drum	`x`
`hihat:`	Hi-hat	`x`
`clap:`	Hand clap	`x`
`tom:`	Tom drum	`x`
`cymbal:`	Cymbal / ride	`x`

Custom Samples (URL)

Load any remote audio file as a named channel by declaring its URL on a line by itself:

# Declare the sample (silent line — just registers the channel)
gong: https://tonejs.github.io/audio/berklee/gong_1.mp3
# Use it like any other instrument
gong: x - - - x - - -

The declaration line is silent — it just registers the sample. Subsequent lines with the same name play the sample.

Trigger with x for percussion-style playback
Use note names to pitch-shift the sample relative to C4 base pitch
Any audio format the browser supports works (MP3, WAV, OGG, FLAC…)
The channel appears in the mixer (orange faders) once it's declared

Free sample library (Tone.js CDN)

These are all publicly hosted and work without sign-up:

Drum kits — CR78, KPR77, R8, Techno, LINN, Stark, Kit3, Kit8…

kick: https://tonejs.github.io/audio/drum-samples/CR78/kick.mp3
snare: https://tonejs.github.io/audio/drum-samples/CR78/snare.mp3
hihat: https://tonejs.github.io/audio/drum-samples/CR78/hihat.mp3
tom1: https://tonejs.github.io/audio/drum-samples/CR78/tom1.mp3

Berklee sound library (800+ MP3s: percussion, voice, SFX…)

gong: https://tonejs.github.io/audio/berklee/gong_1.mp3
chime: https://tonejs.github.io/audio/berklee/chime_1.mp3

Full list: https://github.com/Tonejs/audio

Notes

Each space-separated token is one beat (quarter note at your BPM).

C4          → middle C, normal volume
D#5         → D sharp, octave 5
Ab3         → A flat, octave 3
c4          → middle C, soft (lowercase = 40% velocity)
C4          → middle C, loud (uppercase = 80% velocity)

Octave is optional — defaults to 4 if omitted. Range: 0–8.

Rests

-           → silence for one beat
_           → same thing, alternate style

Chords

Square brackets group notes that play simultaneously:

[C4 E4 G4]      → C major chord
[A3 C4 E4]      → A minor chord

Dotted Notes (1.5 beats)

Add . after a note to extend it to 1.5 beats:

C4.         → plays for 1.5 beats instead of 1
[C4. E4 G4] → whole chord lasts 1.5 beats

Tied Notes (sustain across beats)

Add ~ to hold a note across multiple beats:

C4~ ~ ~     → C4 held for 3 beats total
E4~ ~       → E4 held for 2 beats

Each ~ continuation adds one more beat of duration.

Percussion

Use x or X on drum lines:

kick:  x - x - x - x -
snare: - - x - - - x -
hihat: x x x x x x x x

Putting It Together

Each line is one instrument. Lines play in parallel. Spaces align beats across lines.

piano: [C4 E4 G4] - [F4 A4 C5] - [G4 B4 D5] - [C4 E4 G4] -
synth: c5 - e5 - f5 - g5. -
bass:  C2 C2 C3 C2 F2 F2 G2 G2
kick:  x - x - x - x -
snare: - - x - - - x -
hihat: x x x x x x x x

YAML Format

For longer compositions, use YAML to define reusable sections and arrange them into a song:

bpm: 120

volumes:
  bass: -5
  hihat: -3

instruments:
  synth:
    oscillator: triangle
    attack: 0.05
    release: 1.5
  bass:
    oscillator: square
    filter: 300

sections:
  verse:
    piano: "[C4 E4 G4] - [F4 A4 C5] -"
    bass: "C2 - F2 -"
    kick: "x - x -"

  chorus:
    piano: "[G4 B4 D5] - [C4 E4 G4] -"
    synth: "G5 E5 C5 G4"
    bass: "G2 - C2 -"
    kick: "x - x -"
    snare: "- - x -"

song:
  - verse
  - verse
  - chorus
  - verse
  - chorus x3

YAML Keys

Key	Description
`bpm`	Tempo (overrides the BPM slider)
`volumes`	Per-instrument volume offsets in dB (e.g. `bass: -5`)
`instruments`	Per-instrument synth parameters (see below)
`samples`	URL-based sample channels (see below)
`sections`	Named groups of instrument lines
`song`	Ordered list of section names to play

Custom Samples in YAML

Declare URL-based sample channels under samples:, then use them as instrument lines in your sections:

samples:
  gong: https://tonejs.github.io/audio/berklee/gong_1.mp3
  kick: https://tonejs.github.io/audio/drum-samples/CR78/kick.mp3

sections:
  verse:
    gong: "x - - - - - - -"
    kick: "x - x - x - x -"

Instrument Parameters

Under the instruments key you can configure per-instrument synthesis:

instruments:
  synth:
    oscillator: fatsawtooth  # sine, triangle, square, sawtooth, fatsawtooth, etc.
    attack: 0.03             # seconds
    decay: 0.2
    sustain: 0.4             # 0–1
    release: 1.2             # seconds
  bass:
    oscillator: square
    filter: 200              # lowpass cutoff in Hz
    filterQ: 3               # filter resonance
    attack: 0.01
    sustain: 0.7

Repeats

Append x3 (or *3, X3) to repeat a section multiple times:

song:
  - intro
  - verse x2
  - chorus x4
  - outro

Mixer

Click the mixer icon (sliders) in the transport bar to reveal per-instrument volume controls. The mixer only shows channels that are active in the current composition. Each slider adjusts volume in dB relative to the default mix.

URL-based custom sample channels appear highlighted in orange.

Tips

Dynamics: Alternate c4 (soft) and C4 (loud) for crescendo/decrescendo effects
Multiple lines per instrument: You can have two piano: lines for melody + chords separately
Bass is mono: Only the first note plays if you write a chord on a bass: line
Sharps/flats: Use # for sharp, b for flat — F#4, Bb3, Eb5
BPM range: 40–240, adjustable in the transport bar
Keyboard shortcut: Ctrl+Enter (or Cmd+Enter) to play/stop
Slow instruments: strings: and pad: have slow attacks — leave sustain time so notes bloom
Bell arpeggios: bell: with no sustain creates natural decay; great for melodic patterns
YAML format: Use sections: and song: for verse/chorus structure with repeats