Sigur Ros, ‘Hvarf/Heim’ (XL)
Sigur Rós are hardly renowned for marketing savvy — the title of their third album was a pair of parentheses, thus rendering it only slightly less pronounceable than their 1999 breakthrough, Ágætis Byrjun. But this double album of live and unreleased songs feels cosmically overdue. Hvarf (“Disappeared”) offers five previously unheard cuts; Heim (“Home”) contains six live, acoustic songs from the band’s summer tour through the valleys, fjords, glaciers, and community halls of their native Iceland. Both halves are gripping, but Heim’s unplugged conceit — which spotlights vocalist Jónsi Birgisson’s high, ghostly howls — showcases the band’s eerie pull.