“Marching to the beat of a different drummer” doesn't come anywhere near describing the antics of the Extra Action Marching Band, which forever puts to rest the stereotypical image of the “band geek.” This 30-person ensemble recasts funk and tribal rhythms in Sousaphonic surround sound, its underdressed pompom squad enticing crowds with its come-hither slither. Semi-led by a stilt-walking, megaphone-shouting MC, Extra Action marches wherever it damn well pleases: Protests, street fairs, the Tonga Room, Texas truck stops, BART stations, and private homes have all served as venues. Last year, the crew even crashed a literary reading at Cell Space, forcing David Byrne, Michael Chabon, and Dave Eggers to take a break from signing autographs. (Byrne, unsurprisingly, looked tickled pink by the incursion; later he booked the marchers to open for him at the Fillmore.) To find out where these drum 'n' brass actionists will turn up next, you'll need to check the band's Web site — or just listen for the low, rumbling “oom-pah-pah” next time you're out and about.