Heinrich Isaac (ca. 1450 – 26 March 1517) was a Netherlandish Renaissance composer of south Netherlandish origin. He wrote masses, motets, songs (in French, German and Italian), and instrumental music. A significant contemporary of Josquin des Prez, Isaac influenced the development of music in Germany. Several variants exist of his name: Ysaac, Ysaak, Henricus, Arrigo d'Ugo, and Arrigo il Tedesco among them. (Tedesco means "Flemish" or "German" in Italian.)