Csound Cheat Sheet

Csound's structure in brief — the CSD file layout, the orchestra header, how instruments are written, and the score statements that drive them.

CSD file structure

<CsoundSynthesizer>
<CsOptions>
-odac
</CsOptions>
<CsInstruments>
; orchestra here
</CsInstruments>
<CsScore>
; score here
</CsScore>
</CsoundSynthesizer>

A complete .csd file: options, orchestra, score

-odacOutput to the audio device (-o out.wav writes a file)

Orchestra header

sr = 44100Audio sample rate

ksmps = 32Samples per control period

nchnls = 2Number of output channels

0dbfs = 1Full-scale amplitude — makes 1.0 the maximum

Variable rates (the prefix matters)

asiga-rate: audio, updated every sample

kampk-rate: control, updated every ksmps samples

ifni-rate: set once at note initialisation

gkvalPrefix with g for a global variable

Instruments

instr 1
  asig oscili 0.6, 440
  outs asig, asig
endin

An instrument: opcode outputs on the left, inputs on the right

ares oscili xamp, xcps[, ifn, iphs]The oscili signature — interpolating oscillator

out asig / outs aL, aRSend to the output (mono / stereo)

p4, p5Parameters passed in from the score's i-statement

Common opcodes

oscil, oscili, poscilTable oscillators (poscil is precise)

linen, madsr, expsegEnvelopes

moogladder, butterlp, resonFilters

reverbsc, freeverbReverbs

diskin2, loscilPlay back a sound file / sample

Score statements

i 1 0 2Play instrument 1, start at 0 s, last 2 s

i 1 0 2 440 0.5Extra fields arrive as p4, p5 …

f1 0 128 10 1Build function table 1: GEN10, a sine wave

eEnd the score

t 0 120Set the tempo to 120 BPM

Csound — Veteran synthesis & DSP language. · Csound in the tool directory →

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