Stock Photo: Spanish school. Cantigas de Santa Maria (manuscript with music notations): Clarinet players ('albogues'). 13th century. Canticle n°340. Madrid, San Lorenzo de El Escorial library. Author: ALFONSO X OF CASTILE, THE WISE. Location: MONASTERIO-BIBLIOTECA-COLECCION, SAN LORENZO DEL ESCORIAL, MADRID, SPAIN.