Last year’s Civilian, by the Baltimore duo of singer-guitarist Jenn Wasner and drummer-keyboardist Andy Stack, was one of the year’s understated pleasures. Wye Oak’s latest, the rhythm-driven “Spiral,” takes a new-wavey turn from that album’s smoldering, Americana-smudged indie rock, adding marimba, programmed drums, and mesmerizing vocal effects. It’s no less of an entrancing slow burner, however, and will be available for download today through Adult Swim’s website.