Foo Fighters performing a cover song is nothing new. They have repeatedly shown their love of classic rock acts like KISS and Alice Cooper and Rush among others over the years. But for those who know their Nirvana history, an impromptu jam during a stop in Edinburgh proved to be something quite rare and momentous.

As Dave Grohl was delivering the introductions of the band, he asked guitarist Pat Smear if he had anything he wanted to play. Smear broke into the high energy guitar licks of The Vaselines' "Molly's Lips" with the rest of the Foos picking up on the cue and rocking along with him.

For rock historians, it should be noted that Grohl and Smear's former band, Nirvana, covered "Molly's Lips" and released it as a single in early 1991. Why that's notable is that Foo Fighters have been reticent to perform any Nirvana material since the band started back in the mid-'90s. And while the song is technically a cover, it's one that both Foo Fighters and Nirvana now share.

It's was no coincidence that "Molly's Lips" was the song that Smear chose as The Vaselines, the band that originally recorded the track, hailed from Edinburgh where the Foo Fighters were playing. Check out the fan-shot footage from the show in the player above.

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