It’s official: Paul Giamatti rocks. EW has confirmed that Giamatti is joining the cast of Rock of Ages, a big-screen adaptation of the Broadway musical built around classic hair-band rock songs of the 1980s from groups like Bon Jovi, Journey, Poison, and Whitesnake. As first reported by Deadline, Giamatti will play the manager of a metal band fronted by Stacee Jaxx (Tom Cruise). The cast also includes Mary J. Blige, Russell Brand, and Alec Baldwin. Rock of Ages is slated to begin shooting in May with director Adam Shankman (Hairspray) at the helm, and is scheduled for release on June 1, 2012.