In the Bible, Aaron (אַהֲרֹן) ,, or Aaron the Levite, is the brother of Moses. He was the great-grandson of Levi blank">(Ex. 6:16-20) and represented the priestly functions of his tribe, becoming the first High priest of the Hebrews. While Moses was receiving his education at the Egyptian royal court and during his exile among the _Midianites, Aaron and his sister remained with their kinsmen in the eastern border-land of Egypt. He there gained a name for eloquent and persuasive speech; so that when the time came for the demand upon the Pharaoh to release Israel from captivity, Aaron became his brother’s "nabi", or spokesman, to his own people (Ex. 4:16) and, after their unwillingness to hear, to the Pharaoh himself (Ex. 7:9). He is said to have flourished about 1200 BC (traditionaly 1597 BC )

Aaron was the abbot of St. Martin in Cologne, Germany in the year 1042. He was of Scottish origin, but pilgrimaged in his youth to Colonia to the Scottish convent of St. Martin. He became abbot of the same in 1042. Later, he became abbot of St. Pantaleon. It is believed that he first introduced the Gregorian evening service (nocturns) into Germany. He authored two historically important treaties: De utilitate cantus vocalis et de modo cantandi atque psallendi and De regulis tonorum et symphoniarum. Aaron died on December 14, 1052.

The library of St. Martin conserves his work Tractatum de utilitate cantus vocalis et de modo cantandi atque psallendi.

Aaron was a Miaphysite Coptic saint. His apocryphal legend says of him, "When he was sick, he made roasted pigeons fly into his mouth." He has a feast in the Coptic Calendar of saints on May 16.

Aaron is a saint of the Coptic Church. He has an annual feast in that church on October 19.