HTML5 Piano + Recording Mod

gistfile1.js

// http://bits.potch.me/piano.html
// Copy and paste into console, start playing via keyboard.
// Then, press Z to play back your music!
// Playback deletes recorded music.
var log = []; 
var sinceLast = null; 
document.body.addEventListener('keydown', function(e) {
    if (e.keyCode == 90) { 
        playBack();
    } else {
        var key = getKey(e);
        var i = keyboard.indexOf(key);
        if (i > -1) {
            var now = (new Date()).getTime(); 
            
            if (sinceLast !== null) {
                var duration = now - sinceLast;
                log.push(duration)
            } 
            sinceLast = now;
            log.push(i + 40);
        }
    }
});

function playBack() {
    if (log.length > 0) {
        var note = log.shift();
        var duration = log.shift();
        playNote(note, 0, .5);
        if (duration !== undefined) {
            setTimeout(playBack, duration);
        } else {
            sinceLast = null;
        }
    }
}

// Type log.toSource() to get your recorded work if you haven't played it back yet.
// Sample tune: Paste this in after and hit Z!
log = [45, 434, 49, 440, 51, 751, 45, 461, 49, 482, 51, 762, 45, 451, 49, 545, 51, 476, 56, 466, 54, 706, 51, 449, 52, 456, 51, 442, 47, 448, 44, 1293, 42, 456, 44, 414, 47, 439, 44];