Daseian notation
（重定向自Daseian）
Daseian notation (or dasian notation) is the type of musical notation used in the ninth century anonymous musical treatises Musica enchiriadis and Scolica enchiriadis. The music of the Musica enchiriadis and Scolica enchiriadis, written in Daseian notation, are the earliest known examples of written polyphonic music in history.