Between 1950 and 1970 appears a rebirth in folk music leading by groups such as Los de Ramón, Los Cuatro Huasos and Los Huasos Quincheros, among others with composers such as Raúl de Ramón, Violeta Parra and others. In the mid-1960s native musical forms were revitalized by the Parra family with the Nueva canción Chilena, which was associated with political activists and reformers such as Víctor Jara, Inti-Illimani, and Quilapayún. Other important folk singer and researcher on folklore and Chilean ethnography, is Margot Loyola. Also many Chilean rock bands like Los Jaivas, Los Prisioneros, La Ley, and Los Tres have reached international success. In February, annual music festivals are held in Viña del Mar.