Medieval composer Philippe de Vitry (1291-1361) was also a noted theorist and generally considered one of the intellectual giants of his time. He receives much credit for the development of the motet--which also happens to be the only surviving form of music attributed to him. His ideas for new forms of rhythmic notation and new schemes of rhythm were codified in the seminal work Ars Nova, which lent its name to an entire period of musical history.