For the first time, director Rob Reiner and cocreators Christopher Guest, Michael McKean, and Harry Shearer provide the full behind-the-scenes story of the making of the groundbreaking mockumentary This Is Spinal Tap and its upcoming sequel.

Since its original release in 1984, This Is Spinal Tap has evolved from a beloved cult film into a cinematic landmark: an all-time comedy classic that pioneered an entire genre, the mockumentary. Now, director Rob Reiner and his cowriters and costars, Christopher Guest, Michael McKean, and Harry Shearer, tell the complete story of the movie and its fictitious band—how they met, how Spinal Tap came to be, and how their low-budget indie film took on a life of its own. Years after the movie first came out, the Library of Congress selected This Is Spinal Tap for inclusion in the National Film Registry and Tap went on to play The Royal Albert Hall, Wembley Stadium, and to over 100,000 fans at the Glastonbury Festival in England.

Reiner, Guest, McKean, and Shearer provide the backstories to the movie’s famous lines—among them “Hello, Cleveland!,” “None more black,” “You can’t dust for vomit,” and “These go to eleven”—and to such Tap anthems as “Big Bottom” and “Stonehenge.” Featuring never-before-seen photographs, band memorabilia, and personal reminiscences of their enduring creative partnership, A Fine Line Between Stupid and Clever will delight Tap-heads of all ages—just as the long-awaited Spinal Tap sequel is hitting theaters.

BUT WAIT, THERE’S MORE! A Fine Line Between Stupid and Clever also comes with a bonus memoir by Reiner’s directorial alter ego, Marty DiBergi, in which he interviews Tap band members Nigel Tufnel, David St. Hubbins, and Derek Smalls about their musical journey and their drummers who paid the ultimate sacrifice to the rock gods.