The major triad in color is formed by taking any one of the twelve color-centers of the ophthalmic color scale as the first member of the triad; and, reading up the scale, the fifth step (each step representing a semi-tone) determines the second member, while the third member is found in the eighth step.  The minor triad in color is formed by lowering the second member of the major triad one step; the augmented triad by raising the third member of the major triad one step, and the diminished triad by lowering the third member of the minor triad one step.

[Illustration:  Figure 18.  MAJOR TRIAD, MINOR TRIAD, AUGMENTED TRIAD, DIMINISHED TRIAD]

These various triads are shown graphically in Figure 18 as triangles within a circle divided into twelve equal parts, each part representing a semi-tone of the chromatic scale.  It is seen at a glance that in every case each triad has one of its notes (an apex) in or immediately adjacent to a different one of the grand divisions of the colour scale hereinbefore established and described, and that the same thing would be true in any “key”:  that is, by any variation of the point of departure.

This certainly satisfies the mind in that it suggests variety in unity, balance, completeness, and in the actual portrayal, in color, of these chords in any “key” this judgment is confirmed by the eye, provided that the colors have been thrown into proper harmonic suppression.  By this is meant such an adjustment of relative values, or such an establishment of relative proportions as will produce the maximum of beauty of which any given combination is capable.  This matter imperatively demands an aesthetic sense the most sensitive.

So this “musical parallel,” interesting and reasonable as it is, will not carry the color harmonist very far, and if followed too literally it is even likely to hamper him in the higher reaches of his art, for some of the musical dissonances are of great beauty in color translation.  All that can safely be said in regard to the musical parallel in its present stage of development is that it simplifies and systematizes color knowledge and experiment and to a beginner it is highly educational.

If we are to have color symphonies, the best are not likely to be those based on a literal translation of some musical masterpiece into color according to this or any theory, but those created by persons who are emotionally reactive to this medium, able to imagine in color, and to treat it imaginatively.  The most beautiful mobile color effects yet witnessed by the author were produced on a field only five inches square, by an eminent painter quite ignorant of music; while some of the most unimpressive have been the result of a rigid adherence to the musical parallel by persons intent on cutting, with this sword, this Gordian knot.

Into the subject of means and methods it is not proposed to enter, nor to attempt to answer such questions as to whether the light shall be direct or projected; whether the spectator, wrapped in darkness, shall watch the music unfold at the end of some mysterious vista, or whether his whole organism shall be played upon by powerful waves of multi-coloured light.  These coupled alternatives are not mutually exclusive, any more than the idea of an orchestra is exclusive of that of a single human voice.