MURIS, JOHANNES de. - Astronomer, mathematician, philosopher, and music theorist, born in Normandy before 1300 and died in 1351.
He was at the Sorbonne in Paris, of which he has been thought to have been rector (a Julianus de Muris appears there as rector in 1350); he was a canon in 1344 at Mesières (Bourges); and, as an astronomer, he took part in the work on calendar reform under Clement VI at Avignon. He corresponded with the other great French theorist, Philippe de Vitry, whose theories he defended. The Speculum musicae (recognized as the work of Jacques de Liège) and the Summa musicae are not his. He is, however, the author of the Ars novae musicae (1319) and of Musica speculativa (1323), in which he appears as a farsighted and brilliant precursor of the new theories, occupying a pre-eminent position, especially in the field of emerging polyphony. His works were published in M. Gerbert, Scriptores ecclesiastici de musica sacra, III, St. Blasien 1784, pp. 292-97, 300-301; and in E. de Coussemaker, Scriptores, III, Paris 1870, pp. 398-401 (Anonymus, VI), Conclusiones, III, pp. 109-13. The English translation of the Ars novae musicae is found in O. Strunk, Source readings in music history, New York 1950, pp. 172-79.