In his theoretical tonary "Musica disciplina" Aurelian of Réôme asked a Greek about the meaning of the syllables, and reported that they had no meaning, they were rather an expression of joy as used by peasants to communicate with their working animals like horses.
He earned his doctorate at Yale in 1959, with the dissertation "The Musica Disciplina of Aurelian of Réôme: a critical edition and commentary."