The Cantigas de Santa Maria ("Songs to the Virgin Mary") are manuscripts written in Galician-Portuguese, with music notation, during the reign of Alfonso X El Sabio (1221-1284) and are one of the largest collections of monophonic (solo) songs from the Middle Ages. All of the songs at least mention the Virgin Mary, and every 10th is a religious hymn. Some of the manuscripts containing this music also contain colored miniatures showing pairs of musicians playing a wide variety of instruments.
 
http://en.wikipedia.org/wiki/Cantigas_de_Santa_Maria