Like Bon Iver's For Emma, Forever Ago, Volcano Choir's Unmap is best listened to in isolation. Bon Iver frontman Justin Vernon's side project with members of Wisconsin's Collections of Colonies of Bees results in a bunch of stark, loopy, synthed-out tracks. Like Vernon's other work, the album is a masterpiece of layered vocals. His warm, heart-wrenching falsetto rings out in harmonic choruses. Unlike Bon Iver, Volcano Choir's music follows no pattern or tempo and isn't dominated by guitar. The cool, oddball "Island, Is" is the most accessible track, with looped beats and melodies that circle around Vernon's howls. On the other hand, "Youlogy" is a freakily beautiful song with a melody resembling "Amazing Grace" and jarring gong hits (take heed when driving — they sound like beeping horns). "Still" is a fleshed-out version of Bon Iver's "Woods" that builds to an immense buzz and gently fizzes out. Unmap puts an eerie, unexpected twist on songs ranging from ambient to acoustic. Just don't throw a party to this music. It's a headphones album. — Sills