JB (Jack Black - "King Kong," "The School of Rock") is a naïve Midwesterner whose strict Christian parents view his burning passion for heavy metal as a mortal sin. After his dad tears down every poster in his bedroom except for a Ronnie James Dio poster on the back of the door, the former Black Sabbath frontman instructs the aspiring young rocker to seek out his fortune no matter what the cost. Subsequently setting his sights on Hollywood and hell-bent to take the world of rock music by storm, JB sneaks out his bedroom window and makes his way to Venice Beach, where he soon meets guitar-strumming slacker KG (Kyle Gass - "Elf"). The rock duo now named Tenacious D set out on a quest to achieve musical immortality by stealing the mythical guitar pick said to instill its owner with unprecedented musical prowess.