John says he isn’t bothered. “There’s room for everything. I don’t mind Engelbert Humperdinck. They’re the cats. It’s their scene.”

Throughout 1966, the band has been challenged by the achievements of new and established rivals on both sides of the Atlantic. The April 15 release of the Rolling Stones’ chart-topping fourth UK (and sixth US) album, Aftermath, marks two firsts for Mick Jagger and Keith Richards: they cowrote every song and recorded the entire album at California’s RCA Studios. On August 15, Jefferson Airplane introduced the “San Francisco sound” with RCA’s release of its debut studio album, Jefferson Airplane Takes Off. On December 9, the Who’s second album, A Quick One, climbs to number 4 on the UK charts.

The Jefferson Airplane lead singer, Grace Slick, who joined the band on October 16, 1966, recalls that if “you were in a rock ’n’ roll band in the ’60s, the only thing you couldn’t do was kill people. Everything else was acceptable. You’re being paid to travel around the world, and people admire you because you’re a rock ’n’ roll star.”

The Beatles rose to fame on the strength of their live performances. Now they must discover a way to enthrall fans from inside the studio.

“I was going through murder,” John says of the uncertain transition.

Then Paul has a brainchild. “How about if we become an alter-ego band, something like, say, ‘Sgt. Pepper’s Lonely Hearts’”? he suggests to John, George, and Ringo. “I’ve got a little bit of a song cooking with that title.”

Studio Two fills with smoke and teacups swimming in cigarette butts as they listen to Paul’s idea for a symphonic concept record. While John strums his guitar, Paul sits close by, playing piano.

Suddenly it’s clear to John how to work Paul’s grand plan. Take “a bunch of songs, and you stick two bits of Pepper in it, and it’s a concept.”

Yet what’s even more certain to all four of them is that the music is far too complicated to ever be performed live.

“Let Sgt. Pepper do the touring,” Paul says, then calls George Martin over to the piano. He’s working on the melody for a song based on that poster Paul saw in John’s house in Weybridge.

“It was all there, the trampoline, the somersets, the hoops, the garters, the horse,” Paul says. “It was Pablo Fanque’s fair, and it said ‘being for the benefit of Mr. Kite’; almost the whole song was written right off this poster.”

John calls out, “It’s a fairground sequence. I want to be in that circus atmosphere. I want to smell the sawdust when I hear that song.”

“John would deal in moods, he would deal in colors,” the producer notes, and he’s learned to translate those signals into instruments.

Those will work, John thinks when he hears the organ, harmonium, and bass harmonica sounds that George Martin provides.