White-girl hip-hop, Tin Pan Alley, light opera, and old-fashioned feminist freak folk are a few components of the precious yet increasingly enjoyable music of peripatetic Iowa-born sisters Bianca Leilani (“Coco”) and Sierra Rose (“Rosie”) Casady. The Casadys are at their most gorgeous and glitchy on their Valgeir Sigurosson–produced Tales of a GrassWidow, and tonight they’ll be dancing, beatboxing, and singing about child brides, nature rape, and history’s end. Backed by various combinations of musicians augmented with toy and electronic instruments, the duo draw upon shamanism, serendipity, and merry-fairy pranksterism. Not unlike Prince Rama, CocoRosie is a sister act, political movement, and art project rolled into one. And we can’t wait to hear their music for Robert Wilson’s forthcoming production of Peter Pan.

Sat., Oct. 12, 8 p.m., 2013