It might seem an odd thing to start such a history with a look at ancient mathematicians and astronomers, but some of them offered important initial cornerstones to later theories on synaesthesia. Around the year 550 B.C., to begin with, the Pythagoreans offered mathematical equations for the musical scales, showing that musical notes could be seen as relationships between numbers. A musical scale, for example, could be divided into eight notes, an “octave” scale, which repeats its sequence as the musical notes proceeded higher or lower. To use a basic example, this could be the C-Major scale on the piano, consisting of just the white keys: C-D-E-F-G-A-B-C. This is also the basic “do-re-mi-fa-so-la-ti-do”.
Almost 200 years later, around 370 B.C. or so, Plato wrote Timaeus, in which the soul of the world is described as having these same musical ratios. A cosmology was emerging in which the planets’ radii (the planets’ order actually varied, depending upon the author) were set with a ratio sequence of 1:2:3:4:8:9. Later, ratios would emerge with the following ratio sequence: Moon = 1; Venus = 2; Earth = 3; Mars = 4; Jupiter = 14; Saturn = 25. This sequence approximated the Greek diatonic musical scale’s ratios, thus the planets were tied to music, and a concept of “the music of the spheres” was initiated.
Shortly after Plato, around 350 B.C., Aristotle wrote to maintain that the harmony of colors were like the harmony of sounds. This set the stage for a later equating of specific light and sound frequencies, as Aristotle’s works were translated and incorporated into European sciences. At about this same time, Archytas of Tarentus (c. 428 – 350 B.C.) introduced the «chromatic» (12-tone) scale to Greece. This was seen as a compliment to the two main scales: the diatonic (a whole-note or full-tone scale); and the enharmonic (quarter-tones). Around 1492, Franchino Gaffurio was re-introducing colorized Greek modal music to Europe, with the following system: Dorian = «crystalline» color; Phrygian = orange; Lydian = red; and Mixolydian = an «undefined mixed color» (which is, admittedly, somewhat vague). By the late 1580’s, the painter Giuseppe Arcimboldo was formally equating «dark» with high pitches and white with low pitches (see Dann 1998) – which is the reverse of the more «normal» trend of low being dark and high being white. Athanasius Kircher, around 1646, developed a system of correspondences between musical intervals and colors, based basically upon complex traditional symbolisms, as follows:
|major sixth||fire red|
|augmented fifth||dark brown|
|major third||bright red|