So here it comes: Legal Torrents provides music via the great BitTorrent peer-to-peer file sharing protocol. The music is licensed under the Attribution-NoDerivs-NonCommercial license by Creative Commons. This means it is free to copy and re-distribute the music as long as the music is not used for commercial activities and no derivative works are produced.
I wonder if this would mean if one could use the music to put it in a non-commercial video.