The members of the musical trio Los panchos were: Alfredo Gill, Chucho Navarro, and Hernando Aviles. Both Gill and Navarro were Mexican and Aviles was from Puerto Rico. This group became very famous during the Golden Years of Mexican Cinema as they appeared in many movies.
The requinto was an instrument invented by one of the members of this musical trio, Alfredo Gill. which later on became a standard sound for the bolero music genre.
[Mariano Prunes, Los Panchos Biography, AllMusic (web)]