Representatives from the massive Jazz Mafia outfit perform every Tuesday night at Bruno's in the Mission with different incarnations of the collective rotating weekly shifts. There can be 20 heads crowding the tiny stage in the cozy nightclub, depending on who's playing. If it's the Realistic Orchestra, you're looking at an 18-piece jazz, funk, and hip-hop ensemble. The Shotgun Wedding Quintet, who fuse electronic sampling with live instrumentation, require even more space. Other lineups, most of which are headed by mafia founder Adam Theis, include the Shotgun Wedding Hip Hop Symphony, Brass Mafia, Jazz Mafia Trio, and Low End Theory. Whoever is playing, the room is almost always packed, making it impossible to get to the bar without inadvertently grinding on someone's crotch, which, depending on your point of view, might be a good thing.