Review: Bon Iver, ‘Bon Iver, Bon Iver’: Aidin Vaziri | Five years ago, a heartbroken Justin Vernon retreated to a hunting cabin in the Wisconsin woods. He emerged several months later with a raw, deeply moving record called “For Emma, Forever Ago.” Its unnervingly quiet songs and weird falsetto flights seemed designed exclusively for empathetic loners with beards. Instead, Vernon’s songs found unlikely fans in the producers of the “Twilight” movies, Peter Gabriel and multiplatinum rapper Kanye West, who tapped him as a prominent guest on his latest album, “My Beautiful Dark Twisted Fantasy.” There was a surreal scene at this year’s Coachella festival, where Vernon, a tall, scraggly man in a white T-shirt, was placed on a platform to perform alongside West’s entourage of glittery dancers. But it turns out it was all a temporary diversion. On his second album as Bon Iver (he also released an album under the name Volcano Choir), Vernon returns to his low-key, folksy roots. This one wasn’t recorded in a log cabin, but the emotional weight of the songs makes it sound as if it were. Sonically, it’s more experimental than its predecessor, with military drums thumping in the distance on the opener, “Perth”; a child’s bicycle bell chiming in “Michicant”; and synths burbling through “Lisbon, OH.” But mostly, the album is built around solitary piano lines and that devastating falsetto, which feels no more secure for all the accolades. The music feels as if it’s suspended in air, as if getting a taste of mainstream pop only confirmed Vernon’s desire to make music that sets a mood but doesn’t require motion. The naive charm of the first album has dissipated a bit, but “Bon Iver, Bon Iver” still feels like a shot of integrity in a world of fake.