(Updated November 2012)
Incompetech Royalty Free Music – Original music pieces created by Kevin MacLeod. To use this license, simply attribute the music in your piece.
Opuzz Free Music Tracsk – FREE royalty free music tracks to be used as web page music, commercials, videos or podcasts.
Free Soundtrack Music – Tracks on this site are available for royalty-free use in films, video games, YouTube videos or other digital multimedia productions.
SonnyBoo – 40 Creative Commons attribution Music, free tracks for anyone to use in any form.