Guillaume Dufay (most probably 1397 - 1474) was an early renaissance composer, and the first of many polyphonic masters from the Low Countries (modern Belgium, the Netherlands, and northern France). He was not an innovator, with the exception of a few late works, and wrote within a stable tradition. He was one of the last composers to make use of mediaeval techniques such as isorhythm, but one of the first to use the harmonies, phrasing, and expressive melodies characteristic of the early Renaissance.