Based on the name, you’d expect Margot & the Nuclear So and So’s to play house-shaking blues-rock with a horn section and a brassy, big-voiced woman singer. Improbably, this Indianapolis band’s new album “Sling Shot to Heaven” (Mariel Recording Company) is mostly quiet, understated pop – 13 tracks with hardly a raised voice, just murmured tones and exquisite, low-key popcraft. They’ll play it live Tuesday at Chapel Hill’s Local 506. Empires and Kate Myers are also on the bill, showtime is 8:30 p.m. and tickets are $12-$14. See local506.com for details.