Diego Ortiz (ca. 1510 ? 1570) was a Spanish composer and musicologist, in service to the Spanish viceroy in Naples (Pedro de Urries) and later to Philip II of Spain. Author of a treatise ? Trattado de Glosas, published in 1553 ? on instrumental variation technique as well as on vocal polyphonic works - eg. magnificats and motets.
His works were recently recorded by Jordi Savall with his ensemble, Hespèrion XXI. Very little is known about his life, hence they are unknown both his birthday (in Toledo) and his death (probably in Naples).
In 1553 he was living in the viceroyalty of Naples, five years after, in 1558, he becomes maestro de capilla at Viceroy's Neapolitan Chapel, the third duke of Alba, Fernando Álvarez de Toledo. We also know in 1565, being Viceroy the duke of Alcalá, Pedro Afán de Ribera, he was maestro de capilla yet.