Audio API example which plays an A minor chord

AudioAPI2.html

<script>

var AFreq = 440;
var CFreq = 261.626;
var EFreq = 329.628;


var audioContext = new AudioContext();
var gainMix = audioContext.createGain();
gainMix.gain.value = 0.1;

var oscilators = [];

addNote(AFreq);
addNote(CFreq);
addNote(EFreq);
startMusic(2000);


function addNote(frequency, gain)
{
  var osc = audioContext.createOscillator();
  osc.type="sawtooth";
  osc.frequency.value = frequency;
  oscilators.push(osc);

  var gainOsc = audioContext.createGain();
  gainOsc.gain.value = gain || 0.1;

  osc.connect(gainOsc);
  gainOsc.connect(gainMix);
}

function startMusic(duration)
{
  console.log(oscilators);

  gainMix.connect(audioContext.destination);

  oscilators.forEach(function(osc)
  {
    osc.start(audioContext.currentTime);
  })

  setTimeout(function(){
    oscilators.forEach(function(osc)
    {
      osc.stop();
    });

  }, duration);
}


</script>