What the hell is Biophilia ? If Björk, Iceland’s resident alien siren-poet, has any say, it’s most certainly more than just her eighth studio album. Recorded partially on an iPad, designed to accompany a series of spacey visual apps, written largely with instruments she invented (including a "gameleste," some sort of Earth-movement pendulum harp), Biophilia has been the subject of so much viral marketing and non-musical hoo-hah that it’s tough to remember that this is actually, you know, a collection of songs. For all its experimentation, Biophilia sounds like another Björk album — not a major reinvention or cataclysmic overhaul. This means a number of things. Most important, there’s still that voice. No matter whether she’s doing quirky show tunes, experimental a cappella, or blaring trip-hop, her acquired-taste of a croon has always run on one mode — jagged, fractured melodies dancing awkwardly like a drunk half-remembering a line-dance, her precious phrasing coated in ecstatic spurts and stammers. Much of the album is moody, slow, and occasionally (as on the brooding "Mutual Core"), tedious. It’s a grower — don’t go in without some time to invest, or the desire to listen multiple times and peel apart these lavishly constructed layers. "Moon" is a gorgeous view from an aimlessly drifting space capsule : all soothing harp, acoustic finger-plucking, and pulsing electro-bass. "Cosmogony" opens with a torrent of voices ascending skyward, racing toward a plateau of gurgling bass and warped brass. "They say back then, our universe was a cold, black egg until the God inside burst out," Björk sings. And there’s something oddly comforting about the frosty, glitchy beats and dubby bass of "Crystalline." When an ear-rupturing avalanche of programmed beats explodes toward the track’s conclusion, it feels like Pangea dramatically splitting at the seams — or, maybe, the universe erupting from its cold, black egg.