Color and Music

The Rainbow Book opened to another page is if it wants to speak:

Color and Music
The Search for the Spectral Song

Those who have attuned themselves speak glowingly of the radiant glory of the inner vision and color, the intoxicating sweetness of melody of these inner planes. Sound and light, then, are one phenomenon at two levels of manifestation.

Max Heindel, in the Rosicrucian Cosmo-Conception (1909) writes:
"The physical world of Form, The Desire World (Astral) that of Color, and the world of Thought (Causal) is the sphere of Tone. Echoes (of this music) reach us in this physical world and are our most elusive possessions, as a tone dies as it is born...As geometrical figures are created by drawing a violin bow over the edge of a glass plate, so the forms around us are the crystallized sound-figures of the archetypal forces of the Heaven Worlds."

That is, the physical plane is only the first of three co-existent planes or levels of reality (or Illusion in a higher sense). This four-dimensional space-time matrix in which we live we call the "real" world. In a second, more subtle regions, usually called the Astral, we are in the domain of COLOR, shape, myths, gods and mystery; an intensely luminous world of which this is inly a dim copy. In a yet highter sphere, the Causal, we are in the world of Form Archetype, number, geometrical figure, and, most importantly, MUSIC, the most direct manifestations of the Eternal. Other travellers divide these successive gradations of subtlety into five or seven planes, but their descriptions generally concur.