The pair joined together in support of Sonic Highways

Foo Fighters kicked off their week long residency on Late Show with David Letterman by covering Black Sabbath’s “War Pigs” with special guest Zac Brown on Monday (Oct 13th).

The rockers will perform on the Late Show with a special guest each night this week in celebration of their new docu-series, Sonic Highways debuting on HBO Friday, October 17th.

Sonic Highways the album will be released on November 10th and features the band writing and recording in eight different musical cities across the U.S.

Watch the performance below.