ccMixter offers a collection of Creative Commons audio tracks that are free to use. ccMixter represents well over 40,000 musicians and composers from all across the globe. The site doesn’t have the best search feature, but if you take some time to browse you can find some quality tracks. ccMixter encourages users to sample, mix, and remix their tracks. You can browse through a library of genres and styles to find your favorites and to add in the background music you are interested in. They want you to use their music to create new music tracks and videos.
Be sure to read the licensing for each track so that you fully understand the legal terms before downloading. ccMixter does not offer any sound effects (SFX).