The legend El Cantar de Roldán was sung during centuries by troubadours all around Europe. In the podcast El Libro Rojo with com Nicolás Asensio Jiménez, we found this legend since its origin to its survival in modern times.
This interview is one of the results of the project The Golden Age of the Romancero: Echoes of traditional ballads in Medieval and Early Modern Spanish Literature.
More information here.