Thank you guys!
Currently I'm testing this solution:
Code:
<SCRIPT TYPE="text/javascript">
<!-- 
var filename="Jingle bells.mid";
if (navigator.appName == "Microsoft Internet Explorer")
    document.writeln ('<BGSOUND SRC="' + filename + '">');
else if (navigator.appName == "Netscape")
    document.writeln ('<EMBED SRC="' + filename + '" AUTOSTART=TRUE WIDTH=150 HEIGHT=20>');
// -->
</SCRIPT>
<NOSCRIPT>
<BGSOUND SRC="Jingle bells.mid">
</NOSCRIPT>