CocoRosie are the Casady sisters - Sierra, whose voice soars to almost parodic operatic heights, and Bianca, whose voice is knotty, nasal, and creepily childlike, making some listeners recoil. For others, it's a brilliantly bizarre combination; as is their music, which brings together elements of dance, pop, folk and hip-hop, using an electric blue harp, a selection of exotic flutes, piano, synth and a human beatboxer named Tez.
It's a cliche to call any eccentric, long-haired, wailing women performers "witchy", but they do swirl their arms as if conjuring this music from the ether. Not that it's too ethereal, in the rarefied, delicate sense of the word - CocoRosie exhibit a swagger and groove that you might not expect from such avant garde pop-boundary-pushers. This lifts and carries some of the more dubious on-record elements: see, for instance, the rap on "End of Time" (from new album Tales of a GrassWidow) or Sierra's vocals on "Smokey Taboo", building to an extended howl that recalls the more intensely bonkers moments of The Phantom of the Opera.
It's a full sensory experience, with visuals given equivalent weight. There's live relayed video projections on the back wall, using a kind of negative effect to distort their faces. And they look odd enough as it is… The sisters are famous for their grotesque make-up: thickly outlined jam-sandwich lips and blacked out front teeth. A clothes line runs across the stage and they costume change constantly, Sierra donning a silver-foil bridesmaid's dress, a cobwebby onesie, a diamanté veil and long gloves while Bianca switches between baggy t-shirts, a black wool pom-pom headdress, concertina-ed drapes, and something best described as a feathery squid mask. It's like watching the last hours of a particularly heavy fancy dress party.
They may play dress-up, but it's deliberately subversive too; CocoRosie must be one of the least vain acts you'll ever see, turning the pop standard of quick-change, increasingly sexy outfits on its head. They're performing gender, but it's intentionally disrupting the "girls in a band = cool/cute/hot" formula.
This risks sounding overly theoretical, and on one level it may be (Bianca has just set up her own radical feminist magazine). "It's, like, proper performance art," I overhear a man say to his friend. Yes - but that needn't mean it’s po-faced or smug, and CocoRosie are also blissfully good fun. Leaping about and hugging each other, they look like they're having a blast. It's easy to fall under the spell.