Diego Ortiz is important to history not only as a leading Spanish composer of the Renaissance era, but also as the author of Trattado di glosas, the first printed instruction book about ornamentation for bowed string orchestras. This was an international success, and was published in Italian. The book contains entirely written-out ornamentations designed to fit specific time periods. The player is directed to determine which ornament was most appropriate, and to write it into his part at the right spot. Furthermore, the work contains studies for bass instruments, treble viol, and keyboard, as well as some madrigals. Like most authentic books on ornamentation and instruction of the period, it is a valuable source of information on performing style of the time. Very little is known about Ortiz's life. He is believed to have been born in Toledo and probably died in Rome, where his trail is lost. He served at the Court in Naples and Rome, and was a phenomenal virtuoso on the gamba. 

The Recercada or Ricercar (meaning "seeking anew")  you'll hear tonight is one of many pieces by Ortiz that features variations on a ground bass. In 1553 Ortiz was living in the viceroyalty of Naples. Five years later, the third duke of Alba, Fernando Álvarez de Toledo, appointed him maestro di cappella of the Chapel Royal of Naples. In 1565 Ortiz still held the post under the Viceroy Pedro Afán de Ribera, duke of Alcalá. A recent study suggests that Diego Ortiz could have been the model for a very relevant personage in the famous work of Paolo Caliari Veronese "The Wedding at Cana".

Ortiz published a collection of polyphonic religious music in 1565 in Venice. Musices liber primus hymnos, Magnificas, Salves, Motecta, psalmos includes sixty-nine compositions for four to seven voices, based on plainchant works. They are stylistically conservative for the period, appropriate to the tastes of the dedicatee, Ortiz's employer, Pedro Afán de Rivera, Dukoe of Alcalá and the Spanish Viceroy in Naples.