Drawing on the work of Christopher Page (The Christian West and Its Singers: The First Thousand Years), Wilken (The First Thousand Years: A Global History of Christianity, 152-3) points out that musical notation and the musical staff was an invention of early medieval monks.
He quotes a letter from the inventor of the musical staff, Guido of Arezzo, which describes Pope John XIX’s reaction to the innovation: “John, of the highest apostolic seat, who now governs the Roman church, hearing the fame of our school and greatly marveling how, by means of our antiphoner [the book with the text and notations], boys might learn chants they had never heard, invited me with three emissaries . . . The Pope . . . frequently turning the pages of our antiphoner as if it were a marvel and studying the prefatory rules, did not leave that place or move from where he sat until he had learned one versicle he had never heard, fulfilling his wish, so that he might as soon as possible discover himself what he scarcely believers in others.”