Hear the Beatles' final song together — and see how they recorded it across five decades

The Fab Four have reunited for one last song.

The Beatles released "Now and Then," based on an unreleased demo from John Lennon, on Thursday, featuring contributions from each of the Fab Four. The track was accompanied by a 13-minute documentary chronicling its complex recording process.

According to the documentary, the song's genesis came from Lennon's widow, Yoko Ono. "I was talking to Yoko, and she said, 'Ah, I think I've got a tape of John,'" George Harrison explains in archival audio in the video. "To hear John's voice, that's a thing that we should cherish. And I'm sure he would have really enjoyed that opportunity to be with us again."

Fifteen years after Lennon's death, Harrison and Ringo Starr convened with Paul McCartney in his studio and worked on creating new Beatles songs based around demos Lennon had recorded in his New York City apartment. They successfully converted two of the demos, "Free as a Bird" and "Real Love," into full-blown Beatles tracks with the help of producer Jeff Lynne. The tracks were released in 1995 and 1996 alongside the Anthology documentary project.

The final demo, "Now and Then," proved to be a bigger challenge. "When we started 'Now and Then,' it was very difficult because John was sort of hidden in a way," Starr says in the video. "It really brought to the fore to the three of us that John's gone."

The rudimentary mixing of Lennon's tape created a problem for the remaining Beatles. "Every time we wanted a little bit more of John's voice, this piano came through and clouded the picture," McCartney explains in the doc. "I think we kinda ran out of steam a bit, and time, and it was like, 'Well, I dunno, maybe we'll leave this one.'"

John Pratt/Keystone/Getty The Beatles: Paul McCartney, Ringo Starr, John Lennon, and George Harrison.

Harrison died from lung cancer in 2001, which "took the wind out of our sails," says McCartney.

However, the restorative efforts by Peter Jackson's team on his Get Back documentary in 2021 yielded new technology that reinvigorated "Now and Then."

"During the course of Get Back, we were paying a lot of attention to the technical restoration," Jackson says. "That ultimately led us to develop a technology which allows us to take any soundtrack and split all of the different components into separate tracks based on machine learning."

The technological breakthrough allowed Lennon's vocals to be separated from the piano track, giving new clarity to the recording. "Now we could mix it and make a proper record of it," McCartney says. "I pulled it out, had a listen to it, and thought, 'Oh, I could actually do the bass a bit better, so why don't I start there?'"

"Paul called me up and said he'd like to work on 'Now and Then,'" Starr says in the video. "He put the bass on, he sent the files to me, I put the drums on."

Harrison had previously recorded guitar tracks when the band tinkered with the song in 1995, so his work made it into the final mix as well. McCartney also played a guitar solo reminiscent of the sunny slide style that Harrison developed during his solo career. "It was really a tribute to George," McCartney says.

Producer Giles Martin — son of the Beatles' longtime producer George Martin — composed string arrangements that evoke some of the band's most beloved songs like "Strawberry Fields Forever" and "I Am the Walrus." The musicians recording the string tracks, however, didn't know they were playing on the Beatles' final song. "We had to put the music out on the stands for the musicians, but we couldn't tell them it was a new Beatles song," McCartney explains. "It was all a bit hush-hush. We pretended it was just something of mine."

Lennon's original lead vocals from 1977 are the loudest in the mix, while the rest of the Beatles provided backing vocals, recorded in both 1995 and 2023.

"All of those memories come flooding back. My God, how lucky was I to have all of those men in my life, and to work with those men so intimately, and to come up with such a body of music!" McCartney says at the end of the video. "To still be working on Beatles music in 2023… wow. We're actually messing around with state-of-the-art technology, which is something the Beatles would have been very interested in. 'Now and Then,' it's probably like the last Beatles song. And we've all played on it, so it is a genuine Beatles recording."

Listen to "Now and Then" below.

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