# Colour-Music: The Art of Mobile Color/Chapter 12

CHAPTER XII
SOME SCIENTIFIC OPINIONS
CONSIDERING the question of the analogy between colour and musical sounds purely from the scientific standpoint, there is, broadly speaking, a general agreement amongst scientific men that there are some remarkable points of resemblance between the respective modes of being of the spectrum-band and the musical octave. In both, the sensations produced upon the eye and the ear are due to variations of frequency of pulsation in the air and the luminiferous ether respectively. But, starting from this broad general statement of fact, there are divergencies of opinion as to how far further resemblances extend, and the question has perhaps been additionally complicated lately by the wide acceptance of the electron theory. As long as we confine it to physical science the path for the investigator ​to follow is, as far as it will take him, a fairly clear one. Physical facts as to the production of colour and of sound can, within certain limits, be definitely stated and compared. But when we come to the consideration of the effects of colour and of sound upon our eyes and ears, and through them upon our minds and emotions, upon memory and association, and upon those springs of suggestion and mental impulse which are so closely connected with art, we are in an altogether different domain and one within which there must necessarily be almost endlessly varied opinions.
Amongst scientific men we shall therefore not be surprised to find that some attach considerable weight to the analogy between the spectrum-band and the octave, and the action of colour and sound upon us mentally and emotionally; and that others attach very little and endeavour to confine themselves solely to the physical outlook. We may, perhaps, go as far as to say that valuable and helpful as is the opinion of men of science with regard to the latter, it is to those who have been trained to observe ​and study the emotional effects of colour and sound upon us, and whose lives have been spent in experimenting upon these influences through the medium of their work—namely, to the artist, to the musician, and also to the psychologist—that we should turn for further assistance in investigating the difficult and interesting questions connected with our subject, many of which press for solution.
But, at the same time, it is of great interest to compare the opinions of various scientific men of eminence, and in this chapter it is therefore proposed to give a brief summary of some of these opinions.
The general points of resemblance between colour and sound struck the earlier men of science very forcibly, and there are numerous references to them in their publications. There is not, however, much profit in going back to these opinions, as the scientific outlook, even with regard to physical science, changes so rapidly; but the following extracts from the works of the earlier authorities of our own time may be of interest:
​Prof. Tyndall wrote:
"The pitch of sound is wholly determined by the rapidity of the vibration. What pitch is to the ear in acoustics, colour is to the eye in the undulatory theory of light. . . . Nevertheless, this great theory of undulation, like many another truth, had to establish by hot conflict its rights and existence. Illustrious names were arrayed against it."
In Ganot's Handbook of Physics occurs the following:
"The analogy between the phenomena of light and sound is very close. . . . A red light is due to a comparatively long undulation and corresponds to a deep sound; while a violet light is due to a short undulation and corresponds to an acuter sound."
Prof. H. Schellen, in his well-known work upon Spectrum Analysis, states:
One of the patterns of arc-lamp, specially designed for mobile colour instruments.
Or again, in Preston's Theory of Light the author writes:
"As the pitch (or musical colour) of a note is determined by the frequency of its vibrations, so it is the frequency of the vibrations in the luminiferous ether that determines the colour."
In the last edition of the Textbook of Physics by A. W. Duff (1910) the matter is still referred to thus:
"It is a matter of common experience that the colour of a beam of light does not change when it enters water, hence frequency rather than wave-length determines colour. Colour is therefore analogous to pitch in sound."
Professor Heinrich Rubens, the great investigator of the infra-red rays, would also appear to group them in octaves as a con​venient method of nomenclature; but I am not aware how far he considers the musical analogy to extend.
Professor R. A. Gregory, who tells me that he considers that the analogies between musical sounds and colour are remarkably close, makes the following statement with regard to the musical octave, which is exceptionally clearly put and may be of interest in any comparison between the two scales of colour and sound.
"The major diatonic scale, such as is represented by the sequence of the white notes of a piano, commencing with the middle C, is built up in the following manner: a second major chord is obtained by starting from C$^1$, the octave of C, and descending in the ratio 6 : 5 : 4. This gives frequencies of 48, 40, and 32; and these correspond to the notes C$^1$, A, and F. This set of three notes is known as the 'sub-dominant chord. Finally, a third major chord is obtained by starting from G, and ascending in the ratio 4 : 5 : 6. This gives frequencies of 36, 45, and 54; and these correspond to the notes G, B, and D$^1$. This is known as the 'dominant chord.' The note D$^1$ is above the octave of C, and its lower ​octave D, having a frequency 27, falls between C and E. Thus we obtain the following sequence of notes into which the octave may be divided:
| Notes | C | D | E | F | G | A | B | C |
| Vibrations per second | 256 | 288 | 320 | 341.3 | 384 | 426.6 | 480 | 512 |
| Frequency | 24 | 27 | 30 | 32 | 36 | 40 | 45 | 48 |
| Interval (compared with C) | 1 | $\scriptstyle {\frac {9}{8}}$ | $\scriptstyle {\frac {5}{4}}$ | $\scriptstyle {\frac {4}{3}}$ | $\scriptstyle {\frac {3}{2}}$ | $\scriptstyle {\frac {5}{3}}$ | $\scriptstyle {\frac {15}{8}}$ | 2 ” |
Leaving the strictly physical side of the matter for a moment, the following observations by Helmholtz are interesting as showing that he felt the limitations of the older arts into which colour enters, and that they therefore occupied a totally different position from music and had less to do with what he calls "pure sensation." They almost suggest regret at the absence of any art using colour for the purpose of influencing the emotions in a similar way to that in which music uses harmonic sounds:
"Music stands in a much closer connection with pure sensation than any other of the arts. The latter rather deal with what the senses apprehend, that is, with the images of outward ​objects, collected by physical processes from immediate sensation. Poetry aims most distinctly of all at merely exciting the formation of images, by addressing itself especially to imagination and memory, and it is only by subordinate auxiliaries of a more musical kind, such as rhythm and imitations of sounds, that it appeals to the immediate sensation of hearing. Hence its effects depend mainly on psychical action. The plastic arts, although they make use of the sensation of sight, address the eye almost in the same way as poetry addresses the ear. Their main purpose is to excite in us the image of an external object of determinate form and colour. The spectator is essentially intended to interest himself in this image and enjoy its beauty; not to dwell upon the means by which it was created."
Many modern painters would not entirely agree with this limitation of the scope of painting, and it has become the fashion to refer much to the means by which a pictorial effect is produced in present-day art criticism, but, nevertheless, Helmholtz' contention is in the main a true one, that music has hitherto stood ​alone as an art in its close connection with pure sensation, and that the other arts being more or less tied to the expression of form and definite ideas cannot use colour in the same kind of way as music uses sound.
Dr. G. D. Macdonald published an interesting book some years since upon "The agreement of the musical and colorific scales," and stated, inter alia, that "the inference is therefore legitimate that if the analogy of the musical scale were taken as a guide, the special points of the spectrum whose respective vibrations would compose a well-tempered diatonic scale of colour may readily be chosen." This, of course, is matter of opinion, and I give the statement with all reservation.
Professor Grove was also struck by the closeness of the apparent relation between sound and colour, and, though the artistic possibilities of the use of colour in similar ways to sound did not strike him in reference to the subject, he said in his Correlation of Physical Forces that "the analogies in the ​progression of sound and light are very numerous."
To summarize briefly. The physicist rightly confines his attention to the physical facts to be observed with regard to the production of colour in the spectrum and in other ways, to theories concerning the nature of light and colour, and to deductions which may be drawn from their physical phenomena, and to what they can tell us with regard to the sources from which they emanate and their chemical, electrical, and other material effects. He experiments upon sound in a similar way and considers it from a like standpoint, and he notes points of physical analogy between the two sets of phenomena, but he leaves the intricate question of the effects of colour and sound upon our senses and our minds to the biologist and the psychologist, as also the deductions which they may draw from their observations. Harmony and discord, contrasts and blending in sound and in colour are, for instance, questions directly concerned with the impressions produced upon us, are complicated by various psychical con​siderations, and are therefore more or less outside the domain of physical science. The latter with its clear and unbiased vision gives us its invaluable assistance up to a certain point, but there it leaves us, as to this question of colour sensations and their mental influences, to pursue our own experiments and make our own deductions.
* ↑ Prof. Tyndall, On Light.
* ↑ Ganot's Physics. Edited by E. Atkinson, PH.D., F.C.S.
* ↑ Prof. H. Schellen, Spectrum Analysis. Edited by Sir W. de W. Abney, F.R.S.
* ↑ A Classbook of Physics, by Prof. R. A. Gregory, p. 345.
* ↑ Helmholtz, Sensations of Tone, p. 2.
* ↑ Sound and Colour, by Dr. G. D. Macdonald, F.R.S.