SLUMBERJACK generates enough EDM megawatts to power a city block. The Perth dance-floor duo of Morgan Then and Fletcher Ehlers wield bass like scepters, unleashing huge drops on “Afraid, Unafraid” and “Take Me.” “Cradle to the Grave” shows a mastery of tension and release that’s cinematic in scope. Alluring vocals from Sydnee Carter, KLP, and Vera Blue add colorful narration and counterbalance.