Part of the scope of my new job requires me to edit corporate videos. I need background music, so I turn to free music released under the Creative Commons License. Some of the artistes simply requested that you credit them when you use it.
Plus, even if you're not looking for background sounds, you can just click around for some new sounds beyond your Beyonces and Pinks.
This page contains many links, but you have to sieve them out yourself: http://www.seabreezecomputers.com/tips/freemusic.htm