(Guillelmus de Mascaudio), French composer and poet; b. probably in Machaut, Champagne, c.1300; d. probably in Rheims, April 13?, 1377. Machaut entered the service of John of Luxembourg, King of Bohemia, about 1323, serving as his secretary until the king's death in 1346. He was granted a canonry in Verdun in 1330, another in Arras two years later, and yet another in Rheims in 1333, retaining the first two until 1335. He settled in Rheims permanently about 1340. From 1346 Machaut was in the service of the French nobility, including the future king Charles V.

Machaut's fame is illustrated by the number of surviving presentation manuscripts dedicated solely to his music. His Messe de Nostre Dame for four voices is the first POLYPHONIC setting of the MASS attributable to one composer. He also wrote 42 BALLADES, 33 VIRELAIS, 23 MOTETS, 22 RONDEAUX, 19 LAIS, a double HOCKET (Hoquetus David), a COMPLAINTE, and a CHANSON ROYAL. His poem Remede de Fortune, considered an early work, contains songs in almost every genre in which he composed. Other poems without music are La Louanges des dames and Le Livre du voir dit, a work of the 1360s that tells the story of Machaut's love for a 19-year-old woman, Péronne d'Armentières.