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 active_k.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 = 4410 ; ksmps = 10 ; nchnls = 1 ; Instrument #1 - a noisy waveform. instr 1 ; Generate a really noisy waveform. anoisy rand 44100 ; Turn down its amplitude. aoutput gain anoisy, 2500 ; Send it to the output. out aoutput endin ; Instrument #2 - counts active instruments at k-rate. instr 2 ; Count the active instances of Instrument #1. kcount active 1 ; Print the number of active instances. printk2 kcount endin </CsInstruments> <CsScore> ; Start the first instance of Instrument #1 at 0:00 seconds. i 1 0.0 3.0 ; Start the second instance of Instrument #1 at 0:015 seconds. i 1 1.5 1.5 ; Play Instrument #2 at 0:01 seconds, when we have only ; one active instance of Instrument #1. i 2 1.0 0.1 ; Play Instrument #2 at 0:02 seconds, when we have ; two active instances of Instrument #1. i 2 2.0 0.1 e </CsScore> </CsoundSynthesizer>