Walk Hard: The Dewey Cox Story (2007)

Following a childhood tragedy, Dewey Cox (John C. Reilly) follows a long and winding road to music stardom. Dewey perseveres through changing musical styles, an addiction to nearly every drug known and bouts of uncontrollable rage, until finally, he wins the heart, but not necessarily the body, of his loyal backup singer, Darlene (Jenna Fischer).