Remember when Public Enemy hooked up with Anthrax for "Bring Tha Noize," a strange combo of revolutionary hip-hop beats and angry heavy metal thrash? Well, it was no "911 is a Joke," but the combo was compelling because it unified the extreme musical forms of the black-white racial divide. Of course, now Slim Shady's put a little cream in the coffee of hip-hop, but the pairing of creepy hip hop troupe Swollen Members and metal insurgents Cage is still fascinating. Swollen Members kinda got their start in San Diego, one of their breakthrough performances coming at the B-Boy Summit down here in the late '90s. They're like the Dungeons and Dragons geeks of alternative hip-hop-mellow, jazzy beats matched with sci-fi, gloom-and-doom lyrics. Cage, meanwhile is one of those anomalies-pure San Diego hair metal that's huge in Germany, man. But at home, for some reason, still just hair metal dudes. Swollen Members, Cage, High and Mighty and Styles of Beyond perform at the Belly Up, 9 p.m. on Dec. 4. $13. 858-481-8140.