c.1400-1474. Netherlandish composer. He was the first of a series of great composers coming from the (especially from the duchy of Burgundy) who gave leadership to the development of polyphonic music until well into the sixteenth century. As with most composers of the period, he was a singer and took holy orders. Like many of his compatriots, he was drawn to Italy, where he spent two significant periods of his life and sang for a time in the papal choir. He wrote a highly interesting motet for the consecration of the duomo in Florence, Santa Maria del Fiore in 1436. A large amount of his music survives, much secular as well as sacred. He composed a cycle of three-part settings of the office hymns for the church year, as well as motets and other liturgical pieces.
Although earlier examples are known, Dufay was the first great master of the unified setting of the ordinary of the Mass, employing a preexistent melody (cantus firmus) as the tenor part, repeated in each section as a unifying device. He seems to have begun the custom of often using a secular melody for this purpose. Especially famous is his L'Homme armé Mass, using a secular melody of disputed origin. Almost every composer of Masses employed this melody in at least one work until it was banned by the