The all-star metal project of Dave Grohl where he played almost all the instruments (outside of lead parts by Bubba Dupree of Void, Kim Thayil of Soundgardenimg, and bass parts by Lemmy) that featured a multitude of vocalists. Dave recorded tracks reminiscent of the singers' respective bands, which he grew up greatly admiring, and sent the recordings to them, with a note stating simply "Send back with vocals."

Complete list of singersCronos (Venomimg) - "Centuries of Sin"Max Cavalera (Soulflyimg, Nailbomb, Sepulturaimg, Cavalera Conspiracyimg) - "Red War"Lemmy Kilmister (Motörheadimg, Hawkwindimg) - "Shake Your Blood"Mike Dean (Corrosion of Conformity) - "Access Babylon"

Kurt Brecht (D.R.I.) - "Silent Spring"Lee Dorrian (Cathedral, Napalm Deathimg) - "Ice Cold Man"Scott 'Wino' Weinrich (Saint Vitus, The Obsessed, Spirit Caravan, The Hidden Hand) - "The Emerald Law"Tom Gabriel Fischer (Apollyon Sun, Celtic Frostimg) - "Big Sky"Snake (Voivod) - "Dictatorsaurus"Eric Wagner (Trouble) - "My Tortured Soul"King Diamondimg (King Diamondimg, Mercyful Fate) - "Sweet Dreams"Jack Black (Tenacious Dimg) - "I Am The Warlock" (hidden track, 8:56-12:08 of "Sweet Dreams")