(b Baeza, c1440; d c1491). Spanish theorist and composer. He taught at Salamanca University, at Bologna (from c1472) and at Rome (c1484-91). His treatise, Musica Practica (1482) marks him as one of the most original music theorists. He claimed that the tetrachord system of Boethius and the hexachord of Guido were too complicated for performers and proposed a new solmization method. He also attacked Boethius's ideas on tuning and pleaded for clarity and practicality in other areas. Many of his ideas were taken up by later theorists, including Glarean, Aaron and Zarlino.