Mastodon's masterpiece broke new ground and spawned legions of imitators upon its release. The Georgia four-piece marry sludge metal with progressive rock, taking the slo-mo metal antics of the Melvins and Black Sabbath, adding a heap of the conceptual and technical flourishes of King Crimson and Neurosis. Leviathan is based on Herman Melville's Moby Dick, revealing the thoughts and struggles of Ahab and his fellow shipmates throughout the record. An essential release for those into their sludge, prog, doom, stoner and post metal.