Columbia College Chicago
YouTube Audio Library of No Copyright Music
Free Music Archive - Check the license attached to each song for rights details.
Jukedeck.com - Sign up for a free account to create your own music. Advanced features available for a fee.
Creative Commons Music Communities - list of many sites that welcome music with Creative Commons licenses
Creative Commons Record Labels - lists labels the produce music with Creative Commons licenses
Creative Commons Legal Music for Videos
Mutopia Project - classical and contemporary scores