This should play if your Web browser has WebAssembly enabled (most do). Most examples will play unless they need to load files. The first time you click Play, Csound will spend a few seconds loading, then play. You can edit this code and replay it.
<CsoundSynthesizer> <CsOptions> ; Select audio/midi flags here according to platform ;;;RT audio out, midi in, note=p4 and velocity=p5 -odac -+rtmidi=virtual -M0d --midi-key=4 --midi-velocity-amp=5 ;-iadc ;;;uncomment -iadc if RT audio input is needed too ; For Non-realtime ouput leave only the line below: ; -o cpsmidinn.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; Required settings for WebAudio: sr = 48000 ksmps = 128 nchnls = 2 nchnls_i = 1 ; sr = 44100 ; ksmps = 32 ; nchnls = 2 0dbfs = 1 massign 0, 1 ;assign all midi to instr. 1 instr 1 ;play virtual keyboard inote = p4 icps = cpsmidinn(inote) asig oscil 0.6, icps, 1 print icps outs asig, asig endin </CsInstruments> <CsScore> f0 20 ;sine wave. f 1 0 16384 10 1 ;play note from score too i1 0 1 60 e </CsScore> </CsoundSynthesizer>