The Foo Fighters are coming out with a new album, Sonic Highways, and they’ve chronicled the process of making the album in a documentary series set to air on HBO. Needless to say, they’ve been pretty busy over the past year. In anticipation of their new album and TV series, the band has taken over The Late Show With David Letterman for the next week, and they got things kicked off in style with a cover of the Black Sabbath classic “War Pigs.” The band’s take on the song was blisteringly faithful, with both Dave Grohl and guest vocalist Zac Brown taking their turns doing their best Ozzy impressions. Grohl also sat down to chat with Letterman about the new album and what his kids have been listening to, among other things. You can check out the performance and the interview below: