composer of sacred and secular music, one of the great masters of the Franco-Flemish style that dominated European music of the Renaissance.

Ockeghem's earliest recorded appointment was as a singer at Antwerp Cathedral (1443–44). He served similarly in the chapel of Charles, Duke de Bourbon (1446–48), and later in the royal chapel. He was chaplain and composer to three successive French kings, Charles VII, Louis XI, and Charles VIII. As treasurer of the wealthy Abbey of Saint-Martin at Tours, he received a handsome salary. Like many of his Flemish contemporaries he traveled widely and used his visits to distant cities to extend his musical knowledge. As a teacher he had great influence on the following generation of composers. His death was mourned in writing by Desiderius Erasmus, whose text was set to music by Johannes Lupi; a Déploration by Molinet was set by Josquin des Prez.

Ockeghem's surviving works include 14 masses, 10 motets, and 20 chansons. His work sounds richer than that of his predecessors Guillaume Dufay and John Dunstable; during Ockeghem's era the instrumentally supported vocal (vocal music) lines of earlier music were gradually modified to make way for sonorous choral harmony. The bass range in Ockeghem's compositions extends lower than in his predecessors' music, and the tenor and countertenor voices cross in and out of each other, creating a heavier texture. The long melodic lines of the different voices cadence in different places, so that a continuous flow of music results. Melodic imitation occurs here and there but is not prominent. His Missa prolationum and Missa cuiusvis toni are examples of his highly developed contrapuntal and canonic (canon) technique, but the strict device of canon, of which he was a master, is subtly used and is rarely apparent to the listener. He frequently used preexistent material as a device for musical unity.

Ockeghem's ten motets include Marian texts, such as Ave Maria, Salve regina, and Alma redemptoris mater, and a complete setting of the responsory Gaude Maria. Unlike other composers of the early 15th century, he wrote his masses (mass) in a style more solemn than that of his secular music. They are normally in four parts (two are in five parts), in contrast to the three parts commonly used in chansons. The melodic lines in the masses are longer than those of the chansons. Melodic imitation is more frequent in the chansons, and the rhythms of the chansons are more straightforward than those of the masses.