“Black hole,” sings Josh Ritter, “are your eyes as empty as they look?” Not the best come-on, perhaps. But roughly a decade after topping a new school of singer-songwriters, Ritter hit a creative wall, and his latest is the sound of him kicking through it. The above is from “Rattling Locks,” maybe his gnarliest song ever, with feedback guitar stalking a morose bass-clarinet line. “Folk Bloodbath” conflates Mississippi John Hurt’s “Louis Collins,” Johnny Cash’s “Delia’s Gone” and the legend of Stackalee, ending up – naturally – in a graveyard. Ritter’s verse is myth-filled, by turns trippy and goofy: See “The Curse,” a parlor-room piano ballad about a mummy and a hot anthropologist. Even at his darkest, love knows no boundaries.