The plot of this heavy-metal Cinderella story may sound like a fairy tale, but it's based on the true story of Tim "Ripper" Owens, the lead singer of a Judas Priest cover band who was asked to front the real thing when Priest's Rob Halford left the band in 1996. A great premise for a movie, right? Right, and the first half of Stephen Herek's heavily fictionalized account of Owens's story is thoroughly engaging, like a greasy version of a STAR IS BORN. The problems lie entirely in the follow-through. Pittsburgh, 1985. By day, Chris Cole (Mark Wahlberg) is a simple machine repairman, who lives with his parents and has turned his bedroom into a shrine dedicated to Engli...