Ana Maria La Rosa Sanchez Corcuera, sister of the famous Tito La Rosa, is a descendent of Quechua Indians of the Peruvian Andes. She creates huacos silbadores, whistling vessels, from clay, the same whistling vessels her brother Tito, a shaman of music, uses in his sacred sound ancestral music of Peru. Peruvian whistling vessels were slip cast, a process involving the pouring of a mixture of clay suspended in water into plaster molds. The Andeans originated the process of slip casting about 500 B.C. and utilized it in the production of various ceramic forms, including the whistling vessels.