Gilberto Alejandro Durán Diaz, known to all as Alejo Durán or "El Negro Grande" (the great black Man) (February 9, 1919 – November 15, 1989) was a Colombian vallenato music traditional composer, singer and accordionist.
Duran was born in El Paso, Cesar and lived his last years in Planeta Rica He is notorious for lyrically "self-flagellating" himself in his songs. In 1968 Duran gained notoriety for winning the first version of the "Vallenato Legend Festival" in the city of Valledupar and is often cited as one of the best Vallenato musician of all times. He died in Montería, Córdoba.
Colombian musician Carlos Vives did cover versions of his songs.
Popular songs he wrote include "Altos del Rosario", "Pedazo de Acordeón," "Fidelina," and "La Cachucha Bacana".