Javascript "piano"

<script src="http://codebase.es/riffwave/riffwave.js"></script>
<script>
function play(e)
{
    var audio = new Audio();
    var wave = new RIFFWAVE();
    var data = [];

    wave.header.sampleRate = 44100;
    wave.header.numChannels = 1;

    var i = 0;
    var length=44100;
    while (i<length)
    {
        var t = 128+127*(Math.sin((i*2*Math.PI*e.offsetX)/length))*(1-i/length);
        data[i++] = t;
    }

    wave.Make(data);
    audio.src = wave.dataURI;
    audio.play();
}
</script>
<body onclick="play(event)"></body>