Poly Working

HTML

<script src="http://stuartmemo.com/qwerty-hancock/qwerty-hancock.js"></script>
<div id='keyboard'></div>

JavaScript

var context = new webkitAudioContext();

var keyboard = qwertyHancock({
    id : 'keyboard',
    width : 500,
    octaves : 1,
    startNote : 'C3'
    
});

var nodes = [];

keyboard.keyDown(function(note,frequency){
    var osc = context.createOscillator();
    osc.frequency.value = frequency;
    osc.connect(context.destination);
    osc.start(0);
    nodes.push(osc);
});

keyboard.keyUp(function(note,frequency){
    for(var i = 0; i < nodes.length; i++){
        console.log(frequency);
        if(Math.round(nodes[i].frequency.value) === Math.round(frequency)){
            nodes[i].stop(0);
        }
    }
});