Rob Reiner shares details of 'Spinal Tap' sequel with Paul McCartney, Elton John cameos

Christopher Guest and Michael McKean performing on stage in a scene from the film This Is Spinal Tap, 1984. (Photo by Embassy Pictures Corporation/Getty Images)

Rob Reiner, director, writer and star of "This is Spinal Tap," said the band is getting back together for a sequel of the classic 1984 mockumentary.

While speaking on the RHLSTP with Richard Herring podcast, Reiner confirmed that production will begin soon with Michael McKean, Harry Shearer, and Christopher Guest reprising their roles as members of the fictional heavy metal band Spinal Tap.

"We’re making a sequel," Reiner told Richard Herring. "We’re going to start shooting in the end of February and everybody’s back."

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Reiner also teased appearances by Paul McCartney, Elton John, Garth Brooks and "a few other surprises" in the film. 

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FILE - Spinal Tap, the band formed for the film "This Is Spinal Tap," plays a rare live performance on June 25, 1984, at Wolfgangs in San Francisco, California. (Photo by Randy Bachman/Getty Images)

McKean, Shearer, and Guest starred as band members David St. Hubbins, Derek Smalls and Nigel Tufnel. The original movie had no script – just a four-page outline that was almost entirely improvised.

Reiner’s first cut of the film was seven hours long. Even the jokes they did have planned — like the infamous "these amps goes to 11" scene — were filmed off-the-cuff.

"The only thing that matters is that you get people that are good at improvising. You have to get people that are good at that," Reiner said of the upcoming sequel during the recent podcast appearance. "If you get people who can improvise and they’re funny, then you’re off to the races."

Reiner’s character, the director Marti DeBergi (styled after Martin Scorsese in The Band concert documentary "The Last Waltz"), will also naturally return.

When "This Is Spinal Tap" was first released, many thought Spinal Tap was a real band. Reiner, who studied rock documentaries like "The Kids Are Alright" and "The Song Remains the Same" for preparation, enlisted a cinematographer, Peter Smokler, with a documentary background. 

What was real and what was parody was almost indistinguishable. Reiner said Sting has since told him he watched it countless times but didn’t know if he should laugh or cry.

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1992: L-R: American actors and comedians Michael McKean, Harry Shearer, and Christopher Guest, in costume as the fictitious British rock band Spinal Tap, at the American Music Awards. McKean, Shearer, and Guest portrayed the heavy metal band in direc

Some bits were taken straight from rock ‘n’ roll lore. The band getting lost on their way to the stage came from an experience by Tom Petty and the Heartbreakers, who may have been enjoying the pre-show backstage atmosphere too much.

"This is Spinal Tap" went on to become one of the most beloved comedies of the ‘80s and a massive influence to countless mockumentaries that have followed. 

In 2002, the mockumentary was selected for preservation by the National Film Registry and deemed "culturally, historically, or aesthetically significant" by the U.S. Library of Congress.

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This story was reported from Cincinnati. The Associated Press contributed.