Jamendo.com - probably the largest source of international CC licensed music, and I find a lot of music for films there.
Originally Posted by Which Lo Pan?
online database with info on songs that aren't copyrighted.
Just to be clear - Creative Commons is a form of licensing and actually is an exercise of copyright, it does not mean the music is not copyrighted. There are a variety of different CC licenses that determine what you can do with the music and it's important to understand them because not all of them let you use the music in a film.