CocoRosie is an American musical duo formed by sisters Sierra Rose Casady ("Rosie") and Bianca Leilani Casady ("Coco") in 2003.

Sierra mainly plays the guitar, piano and harp, and contributes vocals. Bianca sings and manipulates various children's toys/electronic & percussion instruments. CocoRosie performs as a duo and also with other backing musicians on occasion, usually a bassist and either a drummer or beatboxer. They were active for most of 2004, 2005 & 2006 playing dates across the US and making several trips to Europe for tours playing with TV on the Radio, Bright Eyes, Devendra Banhart and others.

In late 2006 they appeared as a featured act at the Touch and Go Records 25th anniversary block party in Chicago along with Big Black, Scratch Acid, Killdozer, The Ex, Uzeda and many others.

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 movemen