Indie rock can sometimes seem like a figure skating competition, where those who can't make their vocals the prettiest instead aim for the highest degree of difficulty. Certain artists-- the Dirty Projectors, Joanna Newsom-- stretch the limits of the seven-note scale, crafting melodies that take longer to resolve than sentences in a German philosophy text. Others go for extremity of tone: the glass-shattering falsetto of Passion Pit, or the chest-rumbling baritone of the National. Frog Eyes' Carey Mercer grafts a combination of these approaches into his own voice, a slippery beast that sounds like it gargles with wax in the morning. And while some bands might settle for those vocal contortions as their only exotic feature, Frog Eyes' arrangements are every bit as unpredictable as Mercer's catalog of shouts, groans, and other odd emphases. At full flight, the band's lengthy epics trace impossibly complex patterns that can be briefly stunning in the rare cases where they improbably collide.