Open Source Soundtracks

CCMixter

• Ccmixter.org hosts music freely shared by artists. The uploaded soundtracks are licensed under Creative Commons licenses, and most are Non Commercial.

There appears to be no way to search by license, but here's some cherry-picked titles, separated by use for commercial or non-commercial.

Commercial Use

• Welcome in the intox by Bluemillenium

Non-Commercial Use

• Pling by Jaspertine - featured in source tractor video
• Alien Orange Lab by My Free Mickey

Others

• Jamendo - [1] - royalty-free access

• Type in Free Techno on Google - http://www.entropymusic.com/ and others
• RoyaltyFreeMusic.com - [2]
• MyMusicStream.com - [3]
• FreeLoops.com - [4]
• Guitar Improv from Lucas. Better than Madonna's Human Nature.

• DJBLUE - Mind Field -
  DJ BLUE / CC BY-NC 3.0
• Awesome soundtrack - what is it? - [5]