Petrus de Cruce (Pierre de la Croix) was active as a cleric, composer and theorist in the late part of the 13th century. His main contribution was to the notational system. Life 13th-century composer, theorist, and scholar, Petrus de Cruce was apparently born in or near Amiens, in north-central France; for dates we know only that he was active in the years around 1290. He held the title of magistar, indicating that he probably studied at the University of Paris. Read more on Last.fm