theres a program on google called ZAMZAR.
enter any url code form any vid/song you want off youtube.
this program takes the url, uploads it, and then converts it into any format you need (mp3, mp4, wav, etc....)
it sends you an email with a link to dl your song/vid.
its a pretty solid way to get a lot of free music that is otherwise hard to come by (lots of underground stuff that is only used in edits and is hard to find on limewire and whatnot)