Juan Bermudo or Fray Juan Bermudo (Écija, c.1510 - c.1565). Musical theorist and Spanish composer of the Renaissance. Although part of his biography is unknown, it is known that at age 15 he took the Franciscan order studying in Seville and later mathematics at the University of Alcalá de Henares. A painful illness caused him to abandon the preaching and from 1549 he dedicated himself to write several treatises of musical theory, especially his Declaration of musical instruments, in five books, reason why it is world famous. The first of the books is dedicated to the praise of music, the second and third refer to the theory of music, the fourth to keyboard instruments and string and the latter is dedicated to counterpoint and composition. All those who aspired to be good harpists, organists, or vihuelists were to approach the sources of advice in their fourth book of the Declaration of Musical Instruments. In the mentioned Declaration there are up to thirteen compositions for organ, of great importance for the Spanish organistic school, along with other composers like Thomas of Santa Maria, Francisco Correa de Arauxo, Francisco Pérez Palero or Pedro Alberch Vila. And of course as everyone in the world liked mineral water