Hughes
In the retrogression of harmonies, a key-note and its trinities, by sounding the same tones as when ascending, leads the ear to the same notes, and the root of each key-note becomes the fifth lower key-note. F, the root of C, becomes key-note; B?, the root of F, the next key-note, and so on. [Harmonies of Tones and Colours, Diagram VII - The Modulating Gamut of the Twelve Keys1, page 29]
Ascending, begin with C in the innermost circle, F being its root. The Key-note C becomes the root of G, G becomes the root of D, and so on. In descending, begin with the octave Key-note C in the outermost circle. F, the root of C, becomes the fifth lower Key-note. F is the next Key-note, and becomes the root of B?, &c. The 12 Keys in their order are written in musical clef below. Lastly, the Keys of C and G, ascending on a keyed instrument, are written in music as descending; therefore, to shew correctly notes and colours meeting, it is necessary to reverse them, and write C below G. All are seen to be complementary pairs in tones and colours. [Harmonies of Tones and Colours, Diagram VII Continued2, page 31e]
1872.—"It gives me great pleasure to write to you on this subject. Music deals more with the imaginative faculty than any other art or science, and possessing, as it does, the power of affecting life, and making great multitudes feel as one, may have more than ordinary sympathy with the laws you work upon. You say 'from E, root of B, the fountain key-note F, root of C, rises.' There is a singular analogy here in the relativities of sounds, as traced by comparing the numbers made together by vibrations of strings with the length of strings themselves, the one is the inverse or the counterchange of the other. The length of B and E are the counterchange of F and C, hence they are twin sounds in harmony." [Harmonies of Tones and Colours, Extracts from Dr. Gauntlett's Letters1, page 48]
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