To search for downloadable music

type this {-inurl:(htm|html|php) intitle:"index of" +"last modified" +"parent directory" +description +size +(wma|mp3) "www.fundazone.com"} in the search bar and replace www.fundazone.com with your favorite band, and you will only find open indexes that contain downloadable music files.

Cool tip. Try it. Hope it works for you ! It's such a weel known trick it seems, a dude has a huge web page dedicated to the technique.