Diego Ortiz was a Spanish composer and music theorist, born around 1510, probably in Toledo, and believed to have died around 1576 in Rome. By 1553 he was living in the Spanish viceroyalty of Naples, and in 1558 the Duke of Alba appointed him maestro di cappella of the Chapel Royal of Naples, a post he still held in 1565 under the Duke of Alcalá. Ortiz published two influential music books: the Trattado de glosas (Rome, 1553), a landmark manual of ornamentation for bowed string instruments issued simultaneously in Spanish and Italian editions, and the Musices liber primus (Venice, 1565), a collection of sixty-nine sacred polyphonic works for four to seven voices.

Ortiz’s Trattado de glosas is considered the first published manual of ornamentation for bowed string instruments and a foundational text for the viola da gamba repertoire, teaching performers how to improvise ‘glosas’ (melodic divisions) over standard Renaissance ground basses such as the Romanesca, Passamezzo, La Spagna, and La Folia. Its recercadas remain a cornerstone of the modern early-viol repertoire and a primary reference for historically informed improvisation, and the treatise’s influence is central to the 20th- and 21st-century revival of the viola da gamba led by performers such as Jordi Savall.

Sources:

• http://www.hoasm.org/IVL/Ortiz.html