
Spanish organist and theorist. Blind from
  birth, he was trained in organ and languages; he studied
  humanities at Salamanca University. In 1538 he traveled with
  Cardinal Pedro Sarmiento de Salinas to Rome, where, at the behest
  of Pope Paul III, he was ordained and given an abbacy. He held
  organ posts for the Viceroy of Naples (1553-58, under Diego
  Ortiz), Sigüenza Cathedral (1559-63), and León
  Cathedral (1563-67); he taught at Salamanca University.(1567-87).
  His 
  De musica libri septem
   (1577) treats proportions, intervals, modes, and tones drawing
  on both classical and modem theorists; it discusses rhythm and
  meter anf carries further many of 
  Zarlino
   's ideas; it contains among its musical examples unique
  specimens of Spanish folksongs as known in the sixteenth
  century. He inspired Fray Luis de León's 
  Oda a Salinas.