ModArchive
A massive collection of free music modules (playable mod files), reviews, ratings and a friendly community. the mod archive has been on the scene for over 10 years and provides access to over 130,000 pieces of music. ketachoochoo!!
http://www.modarchive.com/
Modplug Database
Modplug central is your portal into the free music subculture of the internet. you can download free music, and learn how to make music on your home computer, and download songs all for free!
http://www.modplug.com/
Traxinspace
Traxinspace
http://www.traxinspace.com/