TidbitsOctober 14, 2014 10:56 AM ET

Video: Foo Fighters and Zac Brown covered Black Sabbath's "War Pigs" last night on David Letterman.

Foo Fighters began their week-long residency last night on the Late Show With David Letterman by performing a cover of the Black Sabbath classic "War Pigs" with some help from Zac Brown. You can check out their performance below.