Amid Rome's financial and political disorder in the 1430s, Du Fay took a leave of absence from the choir to serve Amadeus VIII, Duke of Savoy.
Du Fay returned to Italy in 1436, writing his most admired work, the complex motet Nuper Rosarum Flores, which celebrated the consecration of Filippo Brunelleschi's dome for the Florence Cathedral.
For the next eleven years, Du Fay was in Cambrai serving Philip the Good, under whom he may have written now-lost works on music theory.
His erratic career took him throughout Western Europe, forming a 'cosmopolitan style' and an extensive oeuvre which included representatives of virtually every polyphonic genre of his time.
[6] Archival discoveries from this period revealed that the surname was usually spelled as two words in documents of the 14th and 15th century, contrary to musical sources of that time.
[6][9] It seems that Du Fay's parents spelt their surname as 'Du Fayt', but for unknown reasons the composer altered the spelling while active in Italy.
[10] From the evidence of his will, he was probably born in Beersel, in the vicinity of Brussels, the illegitimate child of an unknown priest and a woman named Marie Du Fayt.
During those years he studied with Nicolas Malin, and the authorities must have been impressed with the boy's gifts because they gave him his own copy of Villedieu's Doctrinale Puerorum in 1411, a highly unusual event for one so young.
He had left Rome because of a crisis in the finances of the papal choir while seeking to escape the turbulence and uncertainty during the struggle between the papacy and the Council of Basel.
By 1435 he was again in the service of the papal chapel, but this time it was in Florence – Pope Eugene having been driven from Rome in 1434 by the establishment of an insurrectionary republic there, sympathetic to the Council of Basel and the Conciliar movement.
In 1436 Du Fay composed the festive motet Nuper rosarum flores, one of his most famous compositions, dedicated to and performed at the cathedral of Santa Maria del Fiore in Florence, featuring Filippo Brunelleschi's renowned dome.
[14] Although the law degree was not necessary in holding the canonicate at Cambrai, Du Fay regarded both titles important enough to be mentioned in his funeral monument.
When Niccolò died in 1441, the next Marquis maintained the contact with Du Fay, and not only continued financial support for the composer but copied and distributed some of his music.
[12] The struggle between the papacy and the Council of Basel continued through the 1430s, and evidently Du Fay realised that his own position might be threatened by the spreading conflict, especially since Pope Eugene was deposed in 1439 by the council and replaced by Duke Amédée of Savoy himself, as Pope (Antipope) Felix V. At this time Du Fay returned to his homeland, arriving in Cambrai by December of that year.
In 1444 his mother Marie died, and was buried in the cathedral; and in 1445 Du Fay moved into the house of the previous canon, which was to remain his primary residence for the rest of his life.
[16] After the abdication of the last antipope (Felix V) in 1449, his own former employer Duke Amédée VIII of Savoy, the struggle between different factions within the Church began to heal, and Du Fay once again left Cambrai for points south.
Numerous compositions, including one of the four Lamentationes that he composed on the Fall of Constantinople in 1453, his famous mass based on Se la face ay pale, as well as a letter to Lorenzo de' Medici, survive from this period: but as he was unable to find a satisfactory position for his retirement, he returned north in 1458.
Once again he established close ties to the court of Burgundy, and continued to compose music for them; in addition he received many visitors, including Busnois, Ockeghem,[17] Tinctoris,[18] and Loyset Compère, all of whom were decisive in the development of the polyphonic style of the next generation.
After the destruction of the cathedral during the French Revolution the tombstone was lost, but it was found in 1859 (it was being used to cover a well), and is now in the Palais des Beaux Arts museum in Lille.
His latest secular songs show influence from Busnois and Ockeghem, and the rhythmic and melodic differentiation between the voices is less; as in the work of other composers of the mid-15th century, he was beginning to tend towards the smooth polyphony which was to become the predominant style fifty years later.
[28] A typical ballade is Resvellies vous et faites chiere lye, which was written in 1423 for the marriage of Carlo Malatesta and Vittoria di Lorenzo Colonna[29][30] The musical form is aabC for each stanza, with C being the refrain.
[33] Given the supposed unimportance of the treatise, the biographer Francesco Rocco Rossi questions why Gaffurius would even include the citations, and suggests that perhaps he was relying on the elder composer's authority.
[45] The musicologist Reinhard Strohm considers this misleading, noting that while Binchois "earned his enormous reputation in the one genre in which he excelled as a composer, performer and possibly even poet, Du Fay's creativity unfolded along many more musical lines".
[45] Du Fay was one of the last composers to make use of late-medieval polyphonic structural techniques such as isorhythm, and one of the first to employ the more mellifluous harmonies, phrasing and melodies characteristic of the early Renaissance.
[21] His compositions within the larger genres (masses, motets and chansons) are mostly similar to each other; his renown is largely due to what was perceived as his perfect control of the forms in which he worked, as well as his gift for memorable and singable melody.