“He zapped in. I was amazed at his ability,” John recalls. “We had a great time.”

Elton also adds piano and harmony to “Surprise, Surprise (Sweet Bird of Paradox),” John’s love note to May, but it’s “Whatever Gets You Thru the Night” that he thinks has real hit potential.

“That’ll be your Number One,” Elton predicts.

John scoffs, but Elton is serious. He’s so sure of it, in fact, that the two friends make a steep wager as to just how high it will chart.

If the single hits number 1, John has to perform live onstage at one of Elton’s upcoming tour dates.

“He sang harmony on it and he really did a damn good job,” John explains. “So, I sort of halfheartedly promised that if ‘Whatever Gets You Thru the Night’ became No. 1, which I had no reason to expect, I’d do Madison Square Garden with him.”

When Apple releases the album, on September 26 (October 4 in the UK), critics marvel at the pairing. “Elton John—Elton John????—on keyboards and back-up vocals,” New Musical Express announces, picking up on “a real, desperate rocking edge to” the song, which Rolling Stone calls “the ice cream that follows a tonsillectomy.”

On October 9, 1974, John celebrates his thirty-fourth birthday. A series of music milestones follows in fast succession: Walls and Bridges is certified gold on October 22, and then on November 16, “Whatever Gets You Thru the Night” tops the Billboard charts at number 1, just as Elton predicted.

Elton calls John up. “Remember when you promised…”

To make good on his bet, John will be working on Thanksgiving. At Madison Square Garden.

Before the Elton John show on November 28, John’s stage fright comes roaring back, and he’s gripped with nausea. Elton gives John an onyx medallion inscribed with the name Dr. Winston O’Boogie, an alias John sometimes used, and Yoko sends both musicians gardenias, her favorite flower. When John makes his unannounced appearance, he’s wearing the medallion and has Yoko’s gardenia affixed to his lapel.

The crowd cheers, stunned at the sight of the superstar, who’s about to amaze them one more time.

“I just went up and did a few numbers”—the first being “Whatever Gets You Thru the Night”—“but the emotional thing was me and Elton together,” John says.

The two then sang “Lucy in the Sky with Diamonds,” a Lennon song from Sgt. Pepper that Elton had just covered (with Dr. Winston O’Boogie on guitar and backing vocals) and released as a single. For the concert finale, “we thought we’d do a number of an old estranged fiancé of mine called Paul,” John Lennon tells the crowd. “This one I never sang, it’s an old Beatle number, and we just about know it.”

Elton’s band launches into “I Saw Her Standing There.”