Under the east end of the Morrison Bridge and past a row of tents sheltering many homeless people, 15 militants spill out of cars and piece together an assault. Clenching sticks, mallets, and plates of alloy, the invaders form a circle in a rare dry spot. And then: BOOM, a deafening, controlled explosion.

The Last Regiment of Syncopated Drummers are practicing, and the residents of this underworld are tolerating the nearly intolerable. One man literally sweeps to the beat. Another inhabitant sings. Entranced in their rhythm, it is doubtful the drummers can hear the tobacco-wrecked voice. But that's probably for the best.

The band wears custom earplugs distributed by LRSD founder/snare drummer Greg Odell, a Southern California transplant with bleached blond hair and a hypnotist's voice. "You'll ruin your hearing within a month doing this," he cautions, addressing his cast of street-beat misfits. He treats them like family, passing out earplugs as if they were holiday presents. Bandmates hang on his every word as he outlines resolutions for their 10th new year: defined section leaders, new cadences, and reworking "The Rock Out," their bombastic homage to classic marching beats.

The drums-only band are anchored to Odell's memories of Long Beach in the '70s and '80s, when he was a high school marching band member and fan of the annual Tournament of Roses Parade in Pasadena. He describes LSD trips on the beach, couches lining the parade route, and crowds of a million "going crazy" to the nation's top marching bands. While opening for guitar virtuoso Marnie Stern last June at Holocene, this volume-heavy mobile marching band quietly lined up outside the venue before launching their attack.

"I try to tell the guys to not hit their drums while we're waiting to play and just let it rip while we go in," he says. With cymbal, snare, bass, and tenor players alternately firing and recoiling, it's enough to ask: Are you in a gang? "Yeah, but we don't go beat people up. We just beat the drums."