if you want to upload a song on your cpanel you should upload it as a .zip or .rar cause outherwise its illegal and you would get into trouble!
the easiest way would to not have a index.html file so go to file manager and delete it in ur cpanel then you can go to for example say your url is www.google.com ur ftp would be ftp://www.google.com make sure ur in internet explorer then right click and hit log in. after ur loged in you should be able to drag and drop files as if it was a flash drive or disk. then when you go to ur site, it will have that file, they click it and it dl's to thier comp