I found this website called Songza where you can listen to pretty much every song. I've looked up a few rare ones, a few recent ones, and they all seem to be available. Not just album version, but also live versions, and they're all free for you to listen to. I doubt this is legal, but hey.. it's there.
It's a crazy disco song from an Italian slasher flick called "The House on the Edge of the Park". I have a theory that every great B-horror movie must have at least one disco song, and the scene that contains is simply hysterical.
Behold the glory of "Much More", which has also recently been uploaded to Youtube!
I don't think that's really legal. It's at least in the gray area because it looks like it just searches the web for songs. For example, I typed in Beatles Rain and it came up with a couple dozen results some with John Lennon talking before the song. But, it's probably just like YouTube: small fish in big waters.
First song I typed in the search engine: "F**k You In The Ass" by The Outhere Brothers. Had it. Heard it. Hit it. And still not able to believe how liberal the 1990's were...