CocoRosie are an American duo that was formed by sisters Sierra (Rosie) and Bianca (Coco) Casady in 2003. Sierra and Bianca Casady are American half-Cherokee sisters. Sierra, the older of the two, was born in Iowa, and Bianca was born in Hawaii. Their mother nicknamed them Rosie and Coco, respectively, from which their musical act takes its name. Stylistically they may be assigned to the indie rock, psych folk, folk-tronic genres, and are sometimes associated with the new weird america movement. Sierra who studied Operatic vocal techniques lends the lead vocals and also plays the guitar, harp and flute. Bianca is a percussionist and also beatboxes. The group also uses various objects such as toys to construct their unique sound. They were active for most of 2004, playing dates across the U.S. and making several trips to Europe for tours playing with TV on the Radio, Bright Eyes, Battles, Devendra Banhart and others.
On the 29th of April 2008 Cocorosie will be the first band to perform together with the famous Royal Concertgebouw Orchestra in the Concertgebouw in Amsterdam.