A system for teaching singing and musical rudiments devised by Guido d'Arezzo in the eleventh century. The system consists of a series of interlocking hexachords, that form the gamut, starting with the lowest note "gamma-ut" ( of the bottom of the modern bass clef) through the top of the system . The three hexachords are the natural hexachord with C as "ut", the soft hexachord with F as "ut", and the hard hexachord with G as "ut". In the system, the six scale degrees of the hexachords are represented by the syllables "ut, re, mi, fa, sol, la", so that the only semitone lies between "mi" and "fa", all the other steps being whole tones. The system remained the standard preliminary method of instruction for musicians until 1600. [SLM; GJC
A memory aid developed by Gui d'Arezzo. Since the seventh and eighth centuries, letters designated the first six notes of the scale. Arezzo added to each note the first syllable of a verse from the hymn to St. John the Baptist: Ut queant lacis Resonare fibris Mira gestorum Famuli tuorum Solve polluti Labii reatum. Each verse was to be sung a tone higher than the one before, except the fourth, which was separated from the third by only a semi-tone. This allowed the singer to remember the respective places of tones and semi-tones in the series ut, re, mi, fa, sol, la. This series of six notes forms the basis for solmization, derived from the sol- mi sequence.