Tenacious D are to release their first new album for six years.

The rock duo - made up of Jack Black and Kyle Gass - will drop their fourth studio album, 21-track 'Post-Apocalypto', on November 2, which will feature Nirvana stickman and Foo Fighters frontman Dave Grohl on drums.

An accompanying six-episode YouTube series of the same name will debut on September 28, and each episode of the series, which will feature animations drawn by Hollywood star Jack, will feature new songs by the band.

The official synopsis of the series - which will drop on Fridays from September 28 until the record's release - reads: '''Post-Apocalypto' finds Tenacious D thrust into a world of complete and utter destruction following the drop of an atomic bomb.

''Surviving the attack in classic cinematic fashion (a good old imperishable 1950's refrigerator), the duo quickly learns that new forms of evil have spawned from the blast. One thing becomes apparent - for humanity to prevail, Tenacious D must save the world.

''With unimaginable twists and turns, an insane visit to the White House, a time machine, a space adventure, and the help of some tried and true daddy issues, Post-Apocalypto is as hilarious as it is political, and as brilliant and multi-faceted as its incredible creators. The songs are damn good, too.''

Tenacious D last dropped an album in 2012 when they released 'Rize of the Fenix', following on from 'The Pick of Destiny' in 2006, and their self-titled debut record in 2001.

Dave drummed on several tracks on the duo's first album, and returned for track 'Beelzeboss (The Final Showdown)' on their follow-up album, some of which was recorded at his studio.

He also played drums on the majority of Tenacious D's 'Rize of the Fenix' record.