Overtone Cheat Sheet

Overtone drives the SuperCollider engine from a Clojure REPL. The essentials: making sound with instruments, and scheduling with a metronome.

Setup & sound

(use 'overtone.live)Load Overtone and boot the server

(demo (sin-osc 440))Play a UGen for a few seconds

(definst beep [freq 440]
  (* 0.3 (sin-osc freq)))

Define a playable instrument

(beep 300)Play it; (stop) stops everything

(defsynth …)Define a synth on the server

(sin-osc freq)Sine (also saw, square, pulse)

(env-gen (perc) :action FREE)Percussive envelope; free when done

(lpf sig 800)Low-pass filter a signal

(def m (metronome 120))Create a metronome at 120 BPM

(m)The current beat number

(m 4)The time (ms) of beat 4

(at (m (inc (m))) (beep))Schedule a note on the next beat

(apply-at t #'my-fn args)Schedule a function call

(note :c4)Note name → MIDI number

(chord :c4 :major)The notes of a chord

(scale :c4 :major)The notes of a scale

(midi->hz 60)MIDI number → frequency

Overtone — Clojure toolkit over SuperCollider. · Overtone in the tool directory →