Mortar & Pestle's "U.V." is all radiant synths and glossy production, with pinball sounds giving way to singer Janaysa Lambert singing buoyantly about "sunshine." But the Oakland trio is born out of tragedy — the friend who introduced them died shortly after coming up with the group's name — and the song never forgets that the sun also blinds. "U.V." is the first single from their self-titled debut, due on Post Primal.