The Standardization and Change in Performance Style
For several hundred years, regional variations of the chant continued in what was primarily an oral tradition handed down from one singer to another. Then in the eleventh century, the Italian monk Guido d’Arezzo invented a system of lines and letters to portray the chant melodies. By the end of the twelfth century, square shapes began to be used to indicate pitch. When you look at sheet music or a hymnbook, you see that the music is represented by lines and notes. Modern music uses a later development of what Guido d’Arezzo invented.
Once chant music could be written down, using the newly invented lineand-square note system, the ancient neumes fell out of use. However, while the new notation could show pitches, as does modern musical notation, the system of lines and notes could not show the fluid nuances of rhythm portrayed by the ancient neumes. The oral tradition that had been handed down for generations began to die out and a heavier style of chant developed. This style came to be known as “plainchant,” and remained the style for chant performance until the middle of the nineteenth century.