Harmony is simultaneity and a painting in this respect is a chord--a momentary expression fixed in material media. A melody of light requires succession just as the melody in music. The restless colors of the opal comprise a light melody like the songs of birds. The gorgeous splendor of the sunset compares in magnitude and in its various moods with the symphony orchestra and its powers. Throughout nature are to be found gentle chords, beautiful melodies and powerful symphonies of light and this music of light exhibits the complexity and structure analogous to music. There is no physical relation between music, poetry, and light, but it is easy to lean upon the established terminology for purposes of discussion. Those who would build color-music identical to sound music are making the mistake of starting with a physical foundation instead of basing the art of light-expression upon psychological effects of light. In other words, a relation between light and music can exist only in the psychological realm. These melodies and symphonies of light in nature are admittedly pleasing or impressive as the case may be, but are they as appealing as music, poetry, painting, or sculpture? The consensus of opinion of a large group of average persons might indicate a negative reply, but the combined opinion of this group is not so valuable as the opinion of a colorist or of an artist who has sensed the wonders of light. The unprejudiced opinion of artists is that light is a powerfully expressive and impressive medium. The psychologist will likely state that the emotive value of light or color is not comparable to the appeal of an excellent dinner or of many other commonplace things. But he has experimented only with single colors or with simple patterns and his subjects are selected more or less at random from the multitude. What would be his conclusion if he examined painters and others who have developed their sensibilities to a deep appreciation of light and color? It is certain that the painter who picks up a purple petal fallen from a rose and places it upon a green leaf is as thrilled by the powerful vibrant color-chord as the musician who hears an exquisite harmony of sounds.