Thanks to Joe for recommending this movie

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Plot:
A chance meeting between simple-hearted JB (Jack Black) and slacker KG (Kyle Gass) becomes a pivotal moment in their lives. They become fast friends and make up their minds to form the rock duet Tenacious D. However, the buddies come to the conclusion that to conquer the world is not as simple as it appears at first sight. Unwilling to wait that long, the heroes decide to steal what they think will help them achieve their grandiose goal — a magical guitar pick belonging to a rock & roll-themed museum located not far from their hometown. The ambitious rockers will soon have the world at their feet!

[PAID] 100% Legal Download: Tenacious D in The Pick of Destiny [2006]

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