Ah - OK, I thought it was a quiz! If wikipedia is to be belived, its a bootleg oerformance of Dark Side of the Moon by the Floyd.

They used the pseudonym Screaming Abdabs sometimes.

http://en.wikipedia.org/wiki/Screaming_abdabs

As an aside, did you really pay 15$ ? If it's the real thing it's gotta be worth way more than that?