Take a good-sized dose of the Go-Go's instapop, the look of a Georgetown wet T-shirt contest and an urge to merchandise unequaled since the days of Andy Warhol, and you begin to get an idea of what Josie Cotton's show at the 9:30 club last night was all about.

Led by a keyboard player garbed in black vest and a blond, post-punkabilly coiffured keyboard player, the Josie Cotton Band put on a solid, hard-bopping show of punky garage-pop. Opening with "You Could Be the One," the band ran through the bulk of its debut album, "Convertible Music."

Cotton, looking like a delinquent Joan Rivers in heavy makeup, clingy T-shirt and hip-hugging miniskirt, rocked through one hearty, melodic rocker after another. "Rockin' Kind of Love," often played on local radio stations, was especially powerful.

The opening act, Switchblade, turned in its usual set of hyperkinetic, down-home country and western, rockabilly and rythm and blues. The group performed its current local underground radio hits, "She Makes Me Rock Too Much" and "Tight Blue Jeans," along with a bunch of other originals that sounded exactly like those tracks.

The band members sweated; the crowd reveled in their exertions. When lead guitarist Ratso waggled that five-inch-high sugar-loaf hairdo, the audience went unabashedly wild.