Heinrich Isaac was a Netherlandish composer of south Netherlandish origin during the Renaissance era. He wrote masses, motets, songs, 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.