Giuseppe Tartini - Lettere e documenti / Pisma in dokumenti / Letters and Documents - Volume / Knjiga / Volume II

352 & # # # ww terzo suono third sound for in general one observes in the third sound a certain inconstancy or unordered con- duct that is understood with difficulty, given that nature is used to producing things simply, I confess the surprise caused me by such an observation, and I rather want to believe that Your Reverence, to whom it belongs in particular, has risen above it. It is impossible in tota rerum natura to find a phenomenon which is simpler and more or- dered than this. If the terms are reduced to infinite harmonic progression, as is seen in Figure II, the third sound is infinitely constant in 1/2. It is therefore impossible for it to be simpler. If the intervals are practically changed and are adapted to form a musical tone, as is seen in Figure III, in which the tone constituted on A major third, the result- ing third sounds are A, D, E, that is to say Alamire, Dlasolre, Elami; but who knows better than Your Reverence, that given the tone of Alamire a major third, there can only be two respective cadences to two means, arithmetical and harmonic, with the main note of the tone, called by us plagal and authentic. If one arithmetically divides the octave, ? # # w wœ it will be a plagal cadence. ? # # # w w If one divides the same octave harmonically, ? # # w wœ it will be an authentic cadence. ? # # # w w Our Csolfaut scale is composed from the two tetrachords, ? w w w w 12 9 8 6