Acetone, Friday, April 1, at the Boulder Theater, is opening for Mazzy Star during its upcoming appearance in Colorado, but the band is more than interesting enough to justify getting to the show a little early. Cindy, Acetone's debut on Vernon Yard (a spinoff of the Virgin label), is a noisy, trippy affair, a collection of drones and squalls that is as compelling as it is challenging. Throw the "amateur" tag at Acetoners Richie Lee, Mark Lightcap and Steve Hadley, and it just might stick. Still, the group's fresh-from-the-garage racket makes pawing your way through this sonic jumble a refreshing experience. Or at least a weird one.