Dufay was the most influential composer of the 15th century, and his music was copied, distributed and sung everywhere that polyphony had taken root. Almost all composers of the succeeding generations absorbed some elements of his style. The wide distribution of his music is all the more impressive considering that he died decades before the availability of music printing.
He composed in most of the common forms of the day, including masses, motets, Magnificats, hymns, simple chant settings in fauxbourdon, and antiphons within the area of sacred music, and rondeaux, ballades, virelais and a few other chanson types within the realm of secular music. None of his surviving music is specifically instrumental, although instruments were certainly used for some of his secular music, especially for the lower parts; all of his sacred music is vocal. Instruments may have been used to reinforce the voices in actual performance for almost any of his works. Seven complete Masses, 28 individual Mass movements, 15 settings of chant used in Mass propers, three Magnificats, two Benedicamus Domino settings, 15 antiphon settings (six of them Marian antiphons), 27 hymns, 22 motets (13 of these isorhythmic in the more angular, austere 14th-century style which gave way to more melodic, sensuous treble-dominated part-writing with phrases ending in the "under-third" cadence in Dufay's youth) and 87 chansons definitely by him have survived. But attributing works of questionable authorship to Dufay based on alleged stylistic similarities has been a favorite pastime of musicologists for at least a hundred years, judging from the copious literature on the subject.