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 ; Audio out Audio in -odac -iadc ;;;RT audio I/O ; For Non-realtime ouput leave only the line below: ; -o schedkwhen.wav -W ;;; for file output any platform </CsOptions> <CsInstruments> ; Required settings for WebAudio: sr = 48000 ksmps = 128 nchnls = 2 nchnls_i = 1 ; Initialize the global variables. ; sr = 44100 ; kr = 44100 ; ksmps = 1 ; nchnls = 1 ; Instrument #1 - oscillator with a high note. instr 1 ; Use the fourth p-field as the trigger. ktrigger = p4 kmintim = 0 kmaxnum = 2 kinsnum = 2 kwhen = 0 kdur = 0.5 ; Play Instrument #2 at the same time, if the trigger is set. schedkwhen ktrigger, kmintim, kmaxnum, kinsnum, kwhen, kdur ; Play a high note. a1 oscils 10000, 880, 1 out a1 endin ; Instrument #2 - oscillator with a low note. instr 2 ; Play a low note. a1 oscils 10000, 220, 1 out a1 endin </CsInstruments> <CsScore> ; Table #1, a sine wave. f 1 0 16384 10 1 ; p4 = trigger for Instrument #2 (when p4 > 0). ; Play Instrument #1 for half a second, no trigger. i 1 0 0.5 0 ; Play Instrument #1 for half a second, trigger Instrument #2. i 1 1 0.5 1 e </CsScore> </CsoundSynthesizer>