Background Music?

I stumbled across a couple of sites. They provide music downloads and mp3 stuff. Some of the music you can download for free. I was thinking you could use them for background music, but I'm not sure if you need it or not...

Here:
http://www.newgrounds.com/audio/
http://translate.google.com/translate?hl=en&sl=ja&u=http://www.hmix.net/&prev=/search%3Fq%3Dhttp://www.hmix.net/%26biw%3D1280%26bih%3D655
(Sorry that the link above is so long. I was using Google Translate because it was in Japanese. It helped a bit)
http://translate.google.com/translate?hl=en&sl=ja&u=http://www.senses-circuit.com/&prev=/search%3Fq%3Dhttp://www.senses-circuit.com/%26biw%3D1280%26bih%3D655
(Again, I was using Google Translate)
http://translate.google.com/translate?hl=en&sl=ja&u=http://www.rengoku-teien.com/&prev=/search%3Fq%3Dhttp://www.rengoku-teien.com/%26biw%3D1280%26bih%3D655
(Google Translate again...   )

This was what I found so far. If you do need them, I'll post more sites with music downloads.

EDIT: Got some sound effect sites, too.
http://www.freesfx.co.uk/
https://www.pond5.com/
http://audiojungle.net/