Bermudo, Juan, Spanish music theorist; b. Ecija, Seville, c. 1510; d. Andalusia, after 1555. He first studied theology and devoted himself to preaching. He later turned to music and studied at the Univ. of Alcalá de Henares. He spent 15 years as a Franciscan monk in Andalusia. In 1550 he entered the service of the Archbishop of Andalusia, where Cristóbal de Morales was choir director. The writings of Bermudo constitute an important source of information on Spanish instrumental music of the 16th century. His most comprehensive work is the Declaración de instrumentos musicales(Osuna , 1549 and 1555). It deals with theory, in which his authorities were Gaffurius, Glareanus, and Ornithopar-chus; instruments, including problems of tuning, technique of performance, and repertoire; and critical evaluation of contemporary composers, showing familiarity with the works of Josquin Des Prez, Willaert, and Gombert. Bermudo also wrote El Arte tripharia (Osuna, 1550). Thirteen organ pieces by him are included in F. Pedrell, Salterio Sacro-Hispano.
R. Stevenson, /. B. (The Hague, 1960).
—Nicolas Slonimsky/Laura Kuhn/Dennis McIntire