Saint Yared (Ge’ez: ቅዱስ ያሬድ; 25 April 505 – 20 May 571):

He then returned to Axum at the age of nine, becoming the chief priest in Holy Ark of Sion. Soon after, St. Yared composed “Ariam”. While at Axum, St. Yared created musical notations and alphabets. —Wikipedia