Focused on the musical life of the northern Spanish city of Irún throughout the 19th century, one of its most glorious periods, which has not yet been properly studied. The main musical institution was the music chapel at the Parroquia Santa María del Juncal, and for the first time its administrative structure is analyzed by studying the regulations, the time and circumstances of its activities in the various religious and secular festivals, and the biography and musical activity of the maestros de capilla and organists. The activities of the musical groups that played an active role in the civil festivities, and the music academies and schools are also discussed.