the most important composer of the fourteenth century and is a representative of a new style of music that emerged at this time called the French Ars nova, which represented a growing distinction between the style of sacred and secular music. Machaut is considered the greatest poet in fourteenth-century France, and he was a model for his English contemporary Geoffrey Chaucer. Machaut wrote the texts for most of his works. he composed sacred works as well as dozens of popular songs, called chansons, extolling the virtues of "courtly love." best known as the composer of the Notre Dame Mass (The Mass of Our Lady), which is the first complete musical setting of the Ordinary of the Mass.