Garth and Trisha Turn It Up to 11 in "Spinal Tap II”

Garth Brooks knew stepping into the Spinal Tap universe would be a blast—but he wasn’t prepared for just how happy it would make those closest to him.

“I couldn’t wipe the smiles off the band’s faces,” he said of his players. “This was like a dream come true for them.”

Garth and Trisha Yearwood will make cameos in “Spinal Tap II: The End Continues,” the sequel to Rob Reiner’s 1984 mockumentary “This Is Spinal Tap.” The movie opens Sept. 12.

“Spinal Tap II: The End Continues” reunites the original cast -- Michael McKean, Christopher Guest, and Harry Shearer -- as the fictional band Spinal Tap. Reiner returns as the documentarian Marty DiBergi.

The movie picks up 41 years after the original, with the band members now estranged and facing a final concert to fulfill a contractual obligation.

Garth and Trisha appear alongside fellow music royalty Elton John and Paul McCartney in the long-awaited sequel. Once again, Garth said, his wife proves she’s the secret weapon.

“She comes through in the clutch and absolutely kills her part,” he said.

Much to the delight of Garth’s band, who already knew the complete Spinal Tap music catalog, Garth and Trisha also have a song on the soundtrack. The couple teams for a cover of “Big Bottom” from the original "This Is Spinal Tap.”

The 13-track soundtrack, out the same day via Interscope, includes nine new songs and four reworked Spinal Tap fan favorites

With the original cast back and a soundtrack that blends new songs and revamped Spinal Tap classics, Brooks summed it up best: “This was more fun than I could have ever imagined.”