Heinrich Isaac (c.1450-1517) was a Franco-Flemish composer of the Renaissance, active across much of Europe. Born probably in the Low Countries, he worked in Florence, Innsbruck and at the Habsburg court.

Isaac wrote masses, motets, chansons, German songs and instrumental pieces. His vast motet cycle Choralis Constantinus is among the most important sacred music collections of the period.

His music is fluent, contrapuntally assured and adaptable to many languages and liturgical uses. He combined northern polyphonic craft with the cosmopolitan demands of court and church employment.

Though less familiar than Josquin, Isaac was one of the major composers of his generation. His career shows Renaissance music as a travelling language, carried between chapels, courts and cities.