Final answer:
Hroswitha is the famous German nun known for her chants and sacred songs.
Step-by-step explanation:
The famous German nun known for writing Gregorian chants and a collection of sacred songs called Symphonia (Symphony of the Harmony of Heavenly Revelations) is Hroswitha. She was a canoness of a nunnery in Gandersheim, Germany, during the late 10th century.