The Beatles and the Rolling Stones' rivalry is dead. At least since Paul McCartney joined the Stones on their new album, Hackney Diamonds.

A blockbuster collaboration

The Rolling Stones members Keith Richards, Mick Jagger, and Ronnie Woods, Hackney Diamonds.

Andrew Watts, who worked as a producer on the Rolling Stones' Hackney Diamonds, discussed the experience working with McCartney with Rolling Stone.

“I can't explain what that feels like, but it was the Stones and the Beatles,” he said. “It wasn't heavy for them; it was a f**king blast. And the smile on Paul's face kept getting bigger and bigger.

“We did three or four takes of that. And Paul hit the switch during his bass solo, and Mick [Jagger] literally goes, ‘Come on, Paul, let's hear something' in his Liverpool accent. Like, you can't make it up. Everyone was on fire. We did another tune because we were having so much fun,” the Rolling Stones' producer continued.

“When I was walking Paul out, he literally was like, ‘I just played f**king bass with the Stones — and I'm a f**king Beatle.' He literally said those words. These guys were literally like they were 18 again, and you can hear it in the recording. It's ferocious,” he concluded.

Paul McCartney was a part of the Beatles in the 60s. The Rolling Stones have continued well past the Beatles breakup and just released their first album of original music in nearly two decades. Hackney Diamonds featured a bevy of blockbuster collaborations outside of the one with McCartney. Lady Gaga and Stevie Wonder also appear on the album. The album also debuted at No.3 on the Billboard 200 chart.

Hackney Diamonds is out now.