I've got a lot of Creative Commons music sites in my bookmarks so I'm unloading them all here. Hope it's of some use to everyone! Always be sure to check the sites directly for exact crediting format.
SoundImage by Eric Matyas, (CC BY 4.0)
SoundBlend by Julian Ray, (CC BY 4.0)
Natentine by Marwan Nimra and co., (CC BY 4.0)
Free Music Archive by various, see individual licensing on songs
CCMixter by various, see individual licensing on songs
Musopen by various Classical composers, see individual licensing on songs (think Chopin and Beethoven, most should be Public Domain by now)