The earliest progenitors of the urban styles of rumba (yambú and guaguancó) might have developed during the early 19th century in slave barracks ("barracones") long before the use of the term "rumba" as a genre became established. Such proto-rumba styles were probably instrumented with household items such as boxes and drawers instead of the congas, and frying pans, spoons and sticks instead of guaguas, palitos and claves. While these early precursors of rumba have been barely documented, the direct precursors towards the mid- and late-19th century have been widely studied. Urban rumba styles are rooted in the so-called "coros de clave" and "coros de guaguancó", street choirs that derived from the Spanish "orfeones". In addition, the widespread yuka dance and music of Congolese origin became integrated into such choirs, lending its percussion instruments and dance moves. In addition, the secret Abakuá traditions rooted in the Calabar region of West Africa that prevailed in both Havana and Matanzas also influenced the development of rumba as a syncretic genre.