Twelve Boleros By The World Renowned Mexican Trio-Twelve Boleros by the world-renowned Mexican Trio for Piano Vocal and Guitar. Trio Los Panchos was founded in 1944 by the end of the decade the ensemble was appearing throughout the world. The gentle sound ofthe ensemble's voices and guitars ushered in a remarkable era of Mexican trio popularity. The artists' popularity and the American interest in Latin sounds prompted a flood of competing groups.