“To date, Bon Iver’s Justin Vernon has dominated that niche but potent sub-genre, “vocoder-heavy a capella songs about loneliness in nature.” In 2009, “Woods” altered pop’s course; this year’s darker “715 - cr∑∑ks” attempted to break the conventions that settled in the years following Vernon’s initial cultural earthquake. With “Spell,” the DIY pop artist Emily Reo joins him in that obscure but nour”
