ho sottomano questo script che ti consente di scegliere la musica di sottofondo (sia .mid che mp3)

Se ti diverti con le opzioni puoi scegliere di far partire l'audio in automatico o lasciare la scelta all'utente.Ciao :)

<html>

<head>
<script LANGUAGE="JavaScript">

<!-- Begin
songNum = new Array();
songNum[0] = "#";
songNum[1] = "musica/Ambient1.mp3";
songNum[2] = "musica/Ambient2.mp3";
songNum[3] = "musica/Funk1.mp3";
songNum[4] = "musica/Rock1.mp3";

var music = null;
var track = 0;
var ver = navigator.appName;
function audioCheck(plugName) {
for (var i = 0; i < navigator.plugins.length; i++) {
if (navigator.plugins[i].name.toLowerCase() == plugName.toLowerCase()) {
for (var j = 0; j < navigator.plugins[i].length; j++) {
if (navigator.plugins[i][j].enabledPlugin) {
return true;
}
}
return false;
}
}
return false;
}
function chooseSong(s) { // ie
track = s.options[s.selectedIndex].value;
if (ver == "Microsoft Internet Explorer") {
document.all.music.src = songNum[track];
} else {
songPlay('play');
}
}
function songPlay(cmd) { // netscape
if (audioCheck("LiveAudio")) {
if (cmd == 'play') {
document.musicSource.play(false, songNum[track]);
}
} else {
alert("Non hai i plugins necessari!");
}
}
// End -->
</script>

</head>

<body>
<form name="choose">
<div align="center"><center>

<select size="1" name="track" onChange="chooseSong(this);">
<option value="4" selected>Default</option>
<option value="0">No musica</option>
<option value="1">Ambient1</option>
<option value="2">Ambient2</option>
<option value="3">Funk1</option>
</select> </p>
</center></div>
</form>
<script language="JavaScript">
<!-- Begin
var ver = navigator.appName;
if (ver == "Microsoft Internet Explorer") {
document.write('<bgsound src="musica/Rock1.mp3" ID=music loop=1 AUTOSTART=true>');
} else {
document.write('<embed type="audio/midi" src="imagine.mid" AUTOSTART=false hidden=true VOLUME="90" name="musicSource" MASTERSOUND></EMBED>');
}
// End -->
</script>

</body>

</html>