Guido Aretinus (better known as Guido of Arezzo ) was a music theorist of the Medieval era. He was also a monk of the Benedictine order from the Italian city-state of Arezzo (hence the name). He is regarded as the inventor of modern musical notation (staff notation), which replaced neumatic notation.
Guido invented a method for teaching singers to learn chants in a relatively short time, and quickly became famous throughout north Italy.
