Documentarian Marty DiBergi follows estranged Spinal Tap bandmates David St. Hubbins, Nigel Tufnel and Derek Smalls as they search for a drummer and prepare for a reunion concert in New Orleans. Joined by music royalty Paul McCartney and Elton John, Spinal Tap wrestles with their checkered past to put on a show that they hope will solidify their place in the pantheon of rock 'n' roll.