Sorry I miss read the inital post on wanting it based on the day of week

Try this...
Change each document.write line's src= portion for the different songs you wish to play and their location. Also if you want the audio file to play "loop" change to true.
<body>
<script language="JavaScript" type="text/javascript">
s_date = new Date();
if(s_date.getDay() == 1){
document.write('<embed width=0 height=0 hidden="true" autostart="true" volume="5" loop="false" src="AudioFile1.mp3">');
}
if(s_date.getDay() == 2){
document.write('<embed width=0 height=0 hidden="true" autostart="true" volume="5" loop="false" src="AudioFile2.mp3">');
}
if(s_date.getDay() == 3){
document.write('<embed width=0 height=0 hidden="true" autostart="true" volume="5" loop="false" src="AudioFile3.mp3">');
}
if(s_date.getDay() == 4){
document.write('<embed width=0 height=0 hidden="true" autostart="true" volume="5" loop="false" src="AudioFile4.mp3">');
}
if(s_date.getDay() == 5){
document.write('<embed width=0 height=0 hidden="true" autostart="true" volume="5" loop="false" src="AudioFile5.mp3">');
}
if(s_date.getDay() == 6){
document.write('<embed width=0 height=0 hidden="true" autostart="true" volume="5" loop="false" src="AudioFile6.mp3">');
}
if(s_date.getDay() == 7){
document.write('<embed width=0 height=0 hidden="true" autostart="true" volume="5" loop="false" src="AudioFile7.mp3">');
}
if(s_date.getDay() == 0){
document.write('<embed width=0 height=0 hidden="true" autostart="true" volume="5" loop="false" src="AudioFile0.mp3">');
}
</script>