Guido de Arezzo was one of the first music theorists in our western musical tradition.
The familiar song, "Doe, a Deer" from the musical "The Sound of Music" introduces the syllables used for singing notes at sight – sight-reading. But this concept of using syllables for notes is much older than a Rodgers and Hammerstein musical. Do Re Mi Fa Sol La Ti Do – the familiar major scale comes from what we call the solfege system of sight-reading. We can trace the linage of this practice all the way back to the writings of a Benedictine monk of the early 11th century, Guido de Arezzo.
Guido was educated in the abbey of Pomposa on the Adriatic coast and early on he earned a reputation for his ability to teach singers new plainsong chants, new songs, very quickly. How did he do this? Up to this point, the chants of the church were either memorized or represented with small pen strokes called nuemes. They helped the singer remember the basic shape of the melody, but they were by no means precise. Guido developed a system of accurate notation using lines and spaces to separate each individual note. He then gave names to these notes. This is where we get the alphabetic note names we use today. A B C D E F G – based on what we call the natural minor scale, Guido would have called it a mode.
Later, Guido composed a hymn that was meant to educate singers and teach them how to recognize each individual note of the scale. His Ut queant laxis starts each phrase with a different note ascending step by step much like the Rogers and Hammerstein song. The syllables he used for the introduction of each new note has become the solfege system we use a millennium later.
Ut Re Mi Fa Sol La – Since the time of Guido we have added the note Ti, or in some languages Si, to the end of the scale and replaced the Ut with Do, preferring the hard consonant sound over the soft vowel sound.
These developments of notation and singing practice make Guido de Arezzo one of the most influential figures in Western musical history.