The beginning of the Trecento marked a new awareness among composers and musicians that they were entering a new age in music. This sense of novelty was expressed in the titles of several treatises written about 1320: the Ars Nova of Philippe de Vitry ('New Art', which gave its name to this period), and Johannes de Muris' Ars Novae Musicae (Art of the New Music). (Yudkin, pp. 458-59)