Record producer and Garbage drummer extraordinaire Butch Vig has a longstanding relationship with Foo Fighters frontman Dave Grohl that dates back to the Nirvana days when Vig produced their game-changing ‘Nevermind.' Given their history, it shouldn’t come as a huge surprise that they’ve teamed up again, although it does breed an air of excitement. Add in former Nirvana bassist Krist Novoselic to the mix and things take a turn for the euphoric.

In a recent Tweet, Vig disclosed:

“The last 24 hours have been surreal! Had a great gig at the El Rey last night, and spent today recording with Dave, Krist and special guest!” — Butch Vig (@butchvig)

Although the ‘who’ and the ‘where’ have been disclosed, that still raises a question regarding the ‘what,’ and unfortunately Vig was vague with the details. One could hazard a guess that the three and their mystery guest were working on something for the documentary that Grohl is working on about Sound City Studios where 'Nevermind' and classics like Fleetwood Mac's 'Rumours' were recorded, but it’s pure speculation at this point.

While we're playing guessing games, one can only wonder who that mystery guest is. It’s probably safe to say that it’s not Frances Bean Cobain. The soundtrack to the Sound City Studios project already has contributions from Slipknot's Corey Taylor, Stephen Pearcy and Warren DeMartini of Ratt and Josh Homme, making for quite an eclectic mix.

Check out a short trailer for the documentary here.

[Thanks to Banana 101.5]