Baroness cannot be content with just writing songs. The group’s sludgy metal is about creating layers of feedback and distortion and then climbing on said pile to reach a summit of massive dissonance, at which point monstrous notes loom over the freshly built terrain. In Baroness’s slow-­boiling riff-tinkering, every movement is a mighty thing. The Red Album, the Savannah, Georgia, outfit’s last full production, was packed with lofty titles like “O’Applachia,” “Cockroach En Fleur” and “Rays on Pinion” and lauded by metal authority Revolver as 2007’s top album. Baroness’s early EPs, politely ordered as First and Second, offer more straightforward, proletariat-friendly delights. “Tower Falls,” from First, remains perhaps Baroness’s crowning moment. The track is a sterling war cry pushed into oblivion through manic cymbal strikes, dense guitar squeals and ferociously bearded leader John Baizley’s dismal bellow. For the uninitiated, Baizley is worth a Google for another reason: the guitarist/oracle has an extraordinary, underappreciated knack for crafting opulent canvases out of metal album covers.