8. Mastodon, 'Once More 'Round the Sun'
The bold hooks and sharply defined riffs of Mastodon's sixth studio full-length makes it easy to hear this album as their evolution from prog-sludge wizards to straight-ahead hard rockers — but the reality is actually far more, er, complex. While the songs of Once More 'Round the Sun aren't bound to a conceptual framework like 2004's Leviathan or 2006's Blood Mountain, even the album's more accessible tracks like "The Motherload" and "The High Road" are crammed full of unexpected twists and turns. Its lengthy epics, "Chimes at Midnight" and "Diamond in the Witch House" (the latter a collaboration with Scott Kelly of Neurosis), reveal no loss of adventurousness in the band's instrumental excursions. Ultimately, the best part of Sun is Mastodon's ability to make hooky and visceral music without sacrificing either their metallic muscle or their innate weirdness. D.E.