Foo Fighters kicked off their week-long residency last night with a rocking performance of Black Sabbath’s “War Pigs” with new pal Zac Brown on guitar and shared vocals. The Foos are in the house to support their forthcoming album Sonic Highways as well as the HBO series that accompanies the album, which premieres October 17. The powerful take on the Black Sabbath tune was also preceded by some intro music from the Late Show band including snippets of “Pretender.”

The connection between Brown and the Foos runs deep as of late, as not only does the ZBB frontman and his band employ a cover of “Times Like These” during their shows, but Dave Grohl also produced the band’s obviously-titled The Grohl Sessions: Volume One. The two shared the stage together last year when Grohl joined Zac Brown Band for a cover of “Times Like These.”

Tonight, the band will return to the Late Show stage with special guests Ann and Nancy Wilson from Heart. Watch “War Pigs” below. The band will also perform on Friday in Chicago at the Cubby Bear. Tickets go on sale tomorrow.

Grohl also sat down with Letterman for an interview where he discussed the Sonic Highways process along with his kids and their ever-evolving taste in music.