This Is Spinal Tap (1984)

 The guitar amps that “go up to 11”, the endless succession of dying drummers, the onstage replica model of Stonehenge with dancing dwarves... Christopher Guest’s mockumentary about a crass rock group, directed by Rob Reiner, is one of cinema’s most quotable comedies. According to Noel Gallagher, his brother Liam believed Spinal Tap to be a real band, which explains a lot.