Guillaume Du Fay (/djuːˈfaɪ/ dew-FY, French: ; also Dufay, Du Fayt; 5 August 1397(?) – 27 November 1474) was a French composer and music theorist of the early Renaissance. Regarded as the leading European composer by his contemporaries, his music was widely performed and copied. Du Fay held various music positions during his lifetime, and was associated with the Burgundian School as well as among the first composers of, or at least a predecessor to, the Franco-Flemish School.