I saw CocoRosie live this past November at 930 Club -- GREAT show! And their beatboxing percussionist was awesome. More info:
CocoRosie is composed of cross-disciplinary performance artists Sierra and Bianca Casady. These sisters compose songs that blend styles and references, from hip-hop and reggae through to folk and opera, shaping the most intense of experiences into memorable and evocative pop songs. Each sister has her own persona and vocal delivery; Bianca delivers hard-hitting truths in a childlike voice, while Sierra responds in pure open tones, playing a range of instruments including the harp, flute, piano, and guitar.
CocoRosie is on tour this Fall in support of the release of the sisters' fifth album, Tales Of A Grass Widow, produced in collaboration with Icelandic composer and Björk's longtime collaborator Valgeir Sigurðsson and enriched by a whole host of guest performances.