Monoliths & Dimensions is Sunn O)))’s most audacious album. Each track is different, adding new elements to their core sound (a vast cloud of ultra-heavy, ultra-distorted, room-filling guitar and bass chords that are allowed to rumble out until it seems like the foundations of your house are going to give way). Vocalist Attila Csihar, who intones poetry in a sepulchral baritone and an impossibly thick Dracula accent, is a constant presence, but one track features a female vocal ensemble, another features an all-male chorus, while a third — a salute to Alice Coltrane — features orchestral horns, flute, multiple double basses, and harp. It’s still some of the heaviest music around, but there’s an airiness to it, like someone cracked a skylight in the vast ziggurat in which they dwell, letting a ray of sunshine strike the altar.