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> -odac -d </CsOptions> <CsInstruments> ; Required settings for WebAudio: sr = 48000 ksmps = 128 nchnls = 2 nchnls_i = 1 ; sr = 44100 ; ksmps = 64 ; nchnls = 1 0dbfs = 1 gifn ftgen 0,0,0,1,"fox.wav",0,0,1 gifw ftgen 0,0,1024,20,2,1 instr 1 k1 init 0 kts = p4 kcfs[],krms,kerr,kcps lpcanal k1,1,gifn,1024,ksmps,gifw if kcps > 180 then kcps = 180 endif a1 buzz 0dbfs, kcps, sr/(kcps*2), -1 a3 allpole a1*krms*kerr,kcfs k1 += ksmps*kts if k1 > ftlen(gifn) then k1 = 0 endif a3 dcblock a3 out a3 endin </CsInstruments> <CsScore> i1 0 10 1 i1 10 10 .75 i1 20 10 1.5 </CsScore> </CsoundSynthesizer>