They are four sisters who came from Ibirataia, Bahia, Brazil, and had given this name "Quarteto Em Cy" ("Cy Four"/"Four In Cy") by Vinícius de Moraes and Carlos Lyra because of their names: Cyva, Cynara, Cybele and Cylene.
Their actual formation is: Cyva, Cynara, Cybele and Sonia.
They also joined with MPB-4 to form "Octeto" ("Octet").
When they presented themselves to USA, they were known as "The Girls From Bahia".