School of Rock - Name that tune

What was the song the "teacher" was playing on his SG?
He was "chillin" with his feet on his desk and playing the most interesting chords. I couldn't ID it however...
He was playing a lot of stuff, from Led Zeppelin to AC/DC to who knows what. I really like that movie and can't wait till it comes out on DVD. The soundtrack CD may be available now. The interesting thing that I read in Entertainment magazine was that Black could not get clearance from his record company to use his own songs in the soundtrack. He has a new CD coming out soon, which I think will be R-rated for language and general lewdness. The title will be, "Tenacious D The Complete Masterworks Volume One" on Epic Records. But School of Rock was like a great Disney flick (positive, righteous messages) and I enjoyed watching it with my son. I noticed everyone was smiling while exiting the theater.
"...Black could not get clearance from his record company to use his own songs in the soundtrack." Isn't this interesting? Record companies have been stealing artists blind and treating them like property from day one. Now they are crying "wee, wee, wee all the way home" because teen-age girls are beating them at their own game! Enough of the soapbox. -Of course there were many tunes played throughout the movie. The one I found "new and interesting" was what he (Jack Black) was playing with his feet on his teacher's desk. Arpeggio mixed with strumming. Sounded like it could be Rush or maybe Mettalica -sounded like something I'd like to hear more of.