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 Silent MIDI in -odac -iadc -d -M0 ;;;realtime I/O </CsOptions> <CsInstruments> ; Required settings for WebAudio: sr = 48000 ksmps = 128 nchnls = 2 nchnls_i = 1 ;Simple usage of the xtratim opcode ; sr = 44100 ; ksmps = 10 ; nchnls = 2 ; sine wave for oscillators gisin ftgen 1, 0, 4096, 10, 1 instr 1 inum notnum icps cpsmidi iamp ampmidi 4000 ; ;------- complex envelope block ------ xtratim 1 ;extra-time, i.e. release dur krel init 0 krel release ;outputs release-stage flag (0 or 1 values) if (krel == 1) kgoto rel ;if in release-stage goto release section ; ;************ attack and sustain section *********** kmp1 linseg 0, .03, 1, .05, 1, .07, 0, .08, .5, 4, 1, 50, 1 kmp = kmp1*iamp kgoto done ; ;--------- release section -------- rel: kmp2 linseg 1, .3, .2, .7, 0 kmp = kmp1*kmp2*iamp done: ;------ a1 oscili kmp, icps, gisin outs a1, a1 endin </CsInstruments> <CsScore> f 0 3600 ;dummy table to wait for realtime MIDI events e </CsScore> </CsoundSynthesizer>