There was tension within the band leading up to recording.

The early days of the Beatles had been highly collaborative, but by the time they set out to record The White Album, things had changed. Lennon and McCartney each arrived with their own set of songs to record, and were critical of each other’s contributions. The four members, "clearly didn't like being in one another's company anymore," per Emerick, and often recorded separately with Lennon spending much of the session time with partner Yoko Ono rather than his bandmates. His increasingly erratic behavior didn’t help the band come together, according to the engineer, who wrote that “his mood swings were more severe, and they were occurring more frequently.”

For Emerick, the Fab Four seemed to be living a lie. “The public still believed the Beatles were a band, that John and Paul still wrote together, that the four lads from Liverpool were making a group album," he wrote in his memoir. "Nothing, in fact, could have been further from the truth. Not only were they working separately by that time, they were barely speaking to one another."

Lennon and McCartney got stuck on two particular songs.

As the space between the bandmates widened, Emerick recalled “a study in frustration” following a miserable week spent working endlessly on just two songs, Lennon’s "Revolution" and McCartney’s "Ob-La-Di, Ob-La-Da." Neither artist could quite get their respective track quite right. McCartney in particular “was after a Jamaican reggae feel and he wasn't satisfied that the band had nailed it” and was having trouble with the timing, Emerick wrote. To make matters worse, the young recording engineer wrote that Lennon “openly and vocally detested” Ob-La-Di, Ob-La-Da, calling it “more of Paul’s ‘granny music [expletive].'"

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Lennon eventually “went ballistic.”

Tensions came to a head when McCartney announced he wanted to scrap everything that had been recorded for "Ob-La-Di, Ob-La-Da" and start over. Lennon simply couldn’t take it anymore, their engineer recalled. “John went ballistic,” Emerick wrote. “Ranting and raving, he headed out the door, with Yoko trailing closely behind, and we thought that we'd seen the last of him that evening.” But a few hours later, Lennon returned, having spent the time away in what would turn out to be a pivotal way.

Emerick remembered Lennon announcing that he was more stoned than he had ever been and any of his bandmates ever would be. Then he revealed he had achieved what McCartney had not been able to do alone: get the rhythm for the song down. “‘And this,’ Lennon added with a snarl, ‘is how the [expletive] song should go.’ Unsteadily, he lurched down the stairs and over to the piano and began smashing the keys with all his might, pounding out the famous opening chords that became the song’s introduction, played at breakneck tempo," Emerick's memoir reads.

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McCartney was happy to take the suggestion.

According to Emerick, McCartney was more than receptive his bandmate coming around to the song—even if he had taken a lot of drugs to get him to do so. “'Okay, then, John,’ [McCartney] said in short, clipped words, staring his deranged bandmate straight in the eye. ‘Let’s do it your way,'" the engineer wrote.

While Emerick said that he suspected McCartney was flattered by the attention, McCartney recalled a rather rosier (and less drug-infused) version of events in Barry Miles' 1997 biography, Paul McCartney: Many Years from Now.

"I remember being in the studio with George and Ringo, struggling with an acoustic version of the song," the Beatle said. "John was late for the session but when he arrived he bounced in, apologizing, in a very good mood. He sat down at the piano and instantly played the blue-beat-style intro. We were very pleased with his fresh attitude. It turned us on and turned the whole song around. He and I worked hard on the vocals and I remember the two of us in the studio having a whale of a time."

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