Guido of Arezzo (b. c. ad 990/5) was perhaps the most influential music theorist of all time. He not only wrote one of the most widely read treatises of the Middle Ages, the Micrologus, but he also invented the system of lines for notating music that is still used today and a method of teaching melodies using the syllables ut, re, mi, fa, sol and la.

Guido built a reputation as a gifted teacher, able to train singers to learn chants very quickly and he and a colleague began to write out an antiphoner (a book of chant) in a new system of notation. Later he wrote a prologue to the antiphoner, explaining the notation. He pointed out the advantages of a system where each pitch was represented on a line or in a space; and he showed that an indication of which lines represented C and F meant that singers knew immediately where the semitones fell.

In his new teaching method, a tune to the words of the hymn ‘Ut queant laxis’ was used as a mnemonic to aid the recognition of intervals and phrases. The syllables at the beginning of each line of the hymn form the sequence ut–re–mi–fa–sol–la, and although Guido himself may not have used these syllables for teaching melodies by interval (solmization), they were certainly adopted for this purpose later. The use of the hand to indicate where certain intervals should be sung was not his invention, but he may well have developed something like the diagram of the hand showing the solmization syllables (the so-called ‘Guidonian hand’).

Influences | Early Music Sources | Medieval Era | Classical