Javascript or Below Board:
<script>
function BlogMusic(ID,URL){
if(location.href.match("blog/(main|entry)/" + ID + "$")){
//Created by Agent Moose (smcodes.smfforfree3.com)
document.write('<embed src="' + URL + '" autostart="true" loop="true" hidden="true"><noembed><bgsound src="' + URL + '"></noembed>');
};};
BlogMusic("ID","URL");
</script>
ID = The ID of the user you want to add the music to
URL = The URL of the music.
Add more lines to add more music to a blog section:
BlogMusic("ID","URL");
Enjoy