Tenacious D in The Pick of Destiny

Although Black and Gass describe Tenacious D in The Pick of Destiny as an autobiography, certain freedoms have taken, but of course, when was that not going to happen?

It tells the story of a young JB (Jack Black) who decides to leave his family and hometown behind and form his own rock band. He leaves for Hollywood on his quest and on his way meets guitarist Kyle Grass who is performing on the street. They create their own band: Tenacious D, named for birthmarks found on their behinds. (JB has a birthmark which says: "Tenac", and KG has a mark which reads: "ious D".)

The film continues to show their journey together, in a fictitious manner despite the band being real in life, as they try to find a guitar pick belonging to Satan that allows its users to become rock legends.