In 2003, Machine Head made metal's most triumphant comeback, shrugging off 1999's rap-rock mishap Burning Red with an album (Through The Ashes of Empires) that not only recalled the group's Pantera-grade mid-'90s efforts but also surpassed their standard. This year's politically themed prog-thrash masterpiece The Blackening marks a new career pinnacle. Taking full advantage of five- to ten-minute song lengths, Machine Head incorporates labyrinthine dual-guitar harmonies, churning grooves, frosty acoustic tones and warp-speed eruptions into impressively epic compositions. It's safest to appreciate the band's technical proficiency on the record, because Machine Head's mosh pits might be second only to Slayer's in terms of unrelenting brutality. Flynn throws these feral fans a bone on Blackening's "Wolves," which salutes the "brotherhood of violence."