IN tracing the origin of a harmony, or family of sounds, all divisions must come out of the one, or unit. Two powers are at work—cohesion and separation; a truth continually dwelt upon by the Greek philosophers. In the diagram, the note C may be considered as central, or as placed with four tones below and two above itself.
A key-note developing its harmony may be compared to a seed striking its root downwards, and rising upwards. On striking a note, it sounds from within itself, in a rapid and subdued manner, the six kindred tones necessary to its harmony, and all which do not belong to that individual harmony are kept under; thus all harmonies are in sevens. Each seven forms an ascending and descending series; the ear is aware of the tones, but not of the order in which they rise.
The arrangement of a key-note and the six tones which it sounds may be simply explained by writing tones in a musical clef as notes. In this diagram we have the harmony of C and its root F. Both of these rise from the chasms, and hence this harmony is not so closely linked to that of B, and its root E, as to the other eleven harmonies.
The first trinity of sounds (hereafter called the Primaries) rise veering from left to right; the second trinity (hereafter called the Secondaries) follow, veering from right to left. The life of sound always causes a variety of movement to and fro.
The three lowest of the six tones are complementary pairs with the key-note and its two highest tones. Observe the curious order in which the tones sound, avoiding consecutive fifths. First, we have the key-note and its root, or fellow; next A; then D and its root; and then E, whose root, A, has already sounded between the first and the second pair. B, the fourth and central tone in depth, sounds seventh, and, finding no fellow within the compass of the harmony developing it, is isolated. Observe also how closely a key-note and its kindred tones are linked into each other. The Primaries spring from the key-notes, the Secondaries from the Primaries; the first pair comprises a key-note and a tone of the Primaries, the other two pairs have each a tone of the Primaries and a tone of the Secondaries. The key-note, after giving out its tones in trinities, or
In the progression of harmonies these are always closely linked into each other. If any key-note is taken as central, its root will be the fifth note of its harmony below, and it becomes in its turn the root of the fifth note above. If we add the silent notes, the root of the central note is the eighth below, and becomes the root of the eighth above. To explain the lower series of the notes sounding the six tones from within themselves, the only plan appeared to be to write the tones as notes in musical clef. By reference to Chapter V., we see that the lowest series still sound their tones, and lead the ear to the higher series of a key-note, and the six notes of its harmony, as they follow each other in trinities. [Harmonies of Tones and Colours, Diagram III - The Major Keynotes Developing by Sevens, page 25a]