For Dark Meat, erasing the line between audience and performances is less an idealistic goal than a logistical necessity.

The expansive ensemble from Athens, Ga., whose music combines blues-rock scuzz with the fervor of a touring soul revue and the psychedelic splatter of Albert Ayler's free-jazz freak-outs, counts more than two dozen singers, players and assorted noisemakers among its members.

Even at a relatively trim 17 people (not including members of the opening band or civilians pressed into service to bang drums or shake tambourines), there was little hope of fitting them all onto the cramped stage of Johnny Brenda's Thursday night. So onto the floor they went, bare feet skirting slicks of spilled beer, spreading through the crowd with trumpets, violins, and the occasional piccolo.

A spindly young thing with symbols finger-painted on his shirtless chest appeared in the balcony with a tuba slung over his shoulders, blasting oompahs from above.

Dark Meat's music involves a substantial degree of deliberate mess, which on Thursday culminated in a free-form jam that all but cleared the room. But songs like "One More Trip" (about a car ride, of course) hung together with surprising force, built on monster riffs played in near-perfect unison. As musicians swapped places and switched instruments, one began to wonder whether there might be a few renegade band geeks under the stage makeup.

The center of Dark Meat's whirlpool is guitarist, singer and ringleader Jim McHugh, whose songs mix utopian visions and expletive kiss-offs. Flanked by female backing singers whose sounds ranged from primordial ululation to girl-group cooing, McHugh flailed at his guitar and screamed into his microphone, jamming it into his pants as a final exclamation point. While the rest of his merry band skronked and squealed, McHugh began to climb the walls, swinging along outside the balcony railing like a playful monkey. Or perhaps he was just looking for breathing room.