ONE OF THE MOST perplexing problems which still confronts scholars interested in the Mexican corrido is the chronology of the genre's development. When in I939 Vicente T. Mendoza wrote his pioneer study, El romance espafol y el corrido mexicano; estudio comparativo,l he was of the opinion that "La elaboraci6n de nuestro corrido como forma definitiva ocupa todo el siglo pasado."2 Fifteen years later, however, in El corrido mexicano; antologia,3 he shifts his position and declares that "El corrido mexicano en su forma ya cristalizada, tal como lo conocemos en la actualidad, despues de que obtuvo su caracter definitivo en plena Revolucion, es relativamente moderno. .. . "