While we all know that the late Kurt Cobain is an irreplaceable force as the frontman of grunge pioneers Nirvana, it’s safe to say that the great Paul McCartney is a pretty solid person to step up in the name of charity.

A few years ago Nirvana drummer Dave Grohl was putting the finishing touches on his film, Sound City, a documentary which marked his directorial debut and told the history of recording studio Sound City Studios in Los Angeles.

Grohl, who recorded the Nirvana album Nevermind at Sound City Studios in 1991, was inspired to create the documentary after it closed down in 2011. Holding the studio dearly in his heart, Grohl also went on to purchase several items from the studio, including the Neve 8028 analog mixing console.

The Foo Fighters frontman was able to recruit Nirvana bass player Krist Novoselic and touring guitarist Pat Smear to appear in the documentary, both of whom contributed to its soundtrack. Sound City: Real to Reel, the album which accompanied the film, saw Grohl found a supergroup of ‘Sound City Players’ and subsequently received two Grammy Awards for ‘Best Compilation Soundtrack for Visual Media’ and ‘Best Rock Song’ for ‘Cut Me Some Slack’.

[MORE] – Rare footage of Kurt Cobain with Nirvana at last ever Los Angeles show

The award winning song, which featured Paul McCartney on vocals, was initially formed after Grohl invited former Beatle McCartney to a jam session with the surviving members of Nirvana—a session which McCartney later described as a “Nirvana reunion”.

Following the major success of the song, the “Nirvana reunion” went live for the first time as part of the ’12-12-12: The Concert for Sandy Relief’, a charity concert that took place at Madison Square Garden in New York City in 2012. The show, held in response to the devastating Hurricane Sandy, included performances from the likes of The Who, Bruce Springsteen, The Rolling Stones, Kanye West and more. To close the concert, however, the show-stopping moment came when Sir Paul McCartney rolled through some Beatles classics.

As a special treat during his set, McCartney welcomed Grohl, Novoselic and Smear to the stage to run through a rendition of ‘Cut Me Some Slack’. With Grohl back on the sticks, Novoselic on bass, Smear on guitar and Macca rocking the vocals with cigar box guitar, see the full performance below.