original_query: Who were some of the notable filín singers during the time period mentioned in the text?
query: Who were some of the notable filín singers during the late 1940s and 1950s?
answer: Notable filín singers of the late 1940s and 1950s included César Portillo de la Luz, José Antonio Méndez, Frank Domínguez, Frank Emilio Flynn, Elena Burke, and Omara Portuondo.