Here are some links to sites that legitematly offer music for free use in non-commercial projects or with low fees for non-commercial use:
http://creativecommons.org/legalmusicforvideos
http://incompetech.com/music/royalty-free/
http://www.audionetwork.com/
http://www.unippm.co.uk/
http://www.productionmusiconline.com/
http://www.pond5.com/
http://www.premiumbeat.com/