DE CRUCE, PIETRO. – Composer and theorist of music of the 13th century, born perhaps in Amiens (and therefore called Ambianensis).
Although he was a strict representative of the period of the two Franconians, he shows a marked tendency toward the 14th century, because he advanced the technique of musical notation through important innovations, such as the division of the perfect breve into 4 semibreves and the use of the « punctum divisionis » to indicate groups of semibreves equivalent to a breve; he freed the « triplum » from modal rhythm and decisively set notation on the path toward a more pronounced mensuralism. One of his « triplum » was printed by J. Wolf, in Geschichte der Mensuralnotation (Leipzig 1925: II, pp. 1–2 and III, pp. 1–5), and subsequently by J. Rokseth, Polyphonies du XIIe siècle. Le ms. II. 196 de la faculté de Médecine de Montpellier (Paris 1936: I, facs. fols. 273–75; III [transcription], no. 254, pp. 81–84).