Aretino, Guido, of Arezzo
Aretino, Guido, Of Arezzo So called because he was born in that city, was a Benedictine monk. and, according to some, abbot of the Monastery of Pomposia, near Ravsenna. He discovered six notes in music, in changing the hymn of St. John, thus:
UT queant laxis Re sonare fibris, Mi ra gestorum FA muli tuorum, SOL ve polluti LA bpii reatum.
In the time of pope John XIX, Guido went to Rome, and was favorably received by the pontiff. Barolnils, in his -Annals, gives a letter written by him to a monk of Pomposia, in which he describes his journey. This monk had assisted him in compiling his Antiphonarium, which he presented to the monastery upon his return. He also wrote a musical work, called Micrologus, and another on the Measure of the Monochord.