Dave Grohl is back at it! It's been revealed that the Foo Fighters frontman has re-teamed with Nirvana bassist Krist Novoselic and 'Nevermind' producer Butch Vig in the studio.

Dave Grohl might not ever sleep. Between his work with Them Crooked Vultures and Foo Fighters, it seems like Dave has been at it non-stop these past few years. His latest project is a documentary on the legendary -- yet now closed -- Sound City Studios, a quiet little place in Los Angeles where legendary records like Nirvana's 'Nevermind' were recorded. Now Butch Vig has revealed that he has once again entered the studio to record Grohl and Novoselic, as well as an unidentified mystery guest.

While we don't know who the mystery artist is, but we can 100% guarantee that it's not Courtney Love. The 3/4 'Nevermind' reunion is likely connected to Grohl's upcoming documentary, but no further details of the recording have been divulged. The trio last collaborated during the sessions for the Foo Fighters' last album, 'Wasting Light,' on the song 'I Should've Known.' Grohl has already revealed that recordings with Corey Taylor, Josh Homme and others will appear on the 'Sound City' soundtrack.