Buzz is a small but powerful Javascript library that allows you to easily take advantage of the new HTML5 audio element. It tries to degrade properly on non-modern browsers.
var mySound = new buzz.sound( "/sounds/myfile", {
formats: [ "ogg", "mp3", "acc" ]
});
mySound.play()
.fadeIn()
.loop()
.bind( "timeupdate", function() {
var timer = buzz.toTimer( this.getTime() );
document.getElementById( "timer" ).innerHTML = timer;
});