Singer-songwriter Stephin Merritt originally conceived Realism, The Magnetic Fields’ third Nonesuch release, as a companion to the group’s brash 2008 Distortion, though the more tremulous listeners among us can rest assured they won’t have to frantically reach for the volume-control knob this time. Realism, at least on its decorous surface, comes across as a flipside to Distortion, the aural opposite of that clangorous homage to industrial pop of the Jesus and Mary Chain.