Michael Keaton isn't a musician, but he plays one in the upcoming holiday drama "Jack Frost" (opening Dec. 11). In the film, the actor sings the blues and plays a mean harmonica as the leader of the fictitious Jack Frost band. Keaton tells EW Online that he's never harbored rock star fantasies, but after performing in "Jack Frost," he understands the allure. "I get why people love it," Keaton says. "It's therapeutic. It's pure expression... I mean, thousands of fans screaming, that's a rush (you) can't imagine."

To prepare for his role, the actor lived the life of a musician, brushing up on his rusty guitar and harmonica chops under the tutelage of former Yes member Trevor Rabin. Together, Keaton and Rabin co-wrote one of the two songs Keaton sings on the soundtrack, which also features Christmas tunes by Hanson and the Spice Girls.

But contrary to Hollywood hunk tradition, Keaton swears he won't follow Keanu Reeves, Kevin Bacon, and Bruce Willis into a semi-pro musical career. "I love music and I have a good ear," Keaton says, but "I'm not going to make that big stupid mistake everyone else does." Too bad Joe Pesci didn't feel the same way.