After a surprising turn into noisy guitar chaos on last year’s “Hot Slob,” Sylvan Esso announced their new album Ow ∞ last month and shared its Sigur Rós-sampling lead single “Concrete Glen.” The song, which incorporates the gorgeous, familiar-yet-alien sound of Jonsi’s vocals from “Svefn-g-englar,” marked a return to the duo’s usual speciality of folk-informed,…...