Music and Colour ( Color ): a new approach to the relationship

© Copyright Ian C. Firth 2007

Related sites:

home.vicnet.net.au/~colmusic/

www.paradise2012.com/visualMusic/musima

The idea that there is a link or correspondence between music and colour is a very old and very persistent one. According to McClain’s (1978) analysis, Plato linked the major second and perfect fifth to yellow and the perfect fourth to red, in an extension of the Pythagorean harmony of the spheres to encompass planets, tones and colours. Aristotle (1984) suggested a parallel between the harmony of colours and the harmony of musical intervals. Newton (1730/1952), when investigating the spectrum of light, linked the intervals tone, minor third, fourth, fifth, major sixth, minor seventh and octave to the colours red, orange, yellow, green, blue, indigo and violet.

The two-dimensional nature of musical notes

Longuet-Higgins (1962, 1987) argued that musical notes occur in a two-dimensional space, fifths-thirds space. The table below shows all the musical intervals recognized by music theory, together with the frequency ratios which define them, in a two dimensional arrangement, one dimension corresponding to the addition or subtraction of perfect fifths, and the other corresponding to the addition or subtraction of major thirds.


Table 1

Musical intervals arranged by ascending or descending fifths and ascending or descending major thirds (after Longuet-Higgins, 1962, 1987)

Augmented seventh
50
27
Augmented fourth
25
18
Small
halftone
25
24
Augmented fifth
25
16
Augmented second
75
64
Augmented sixth
225
128
Augmented third
675
512
Imperfect fifth
40
27
Minor
tone
10
9
Major
sixth
5
3
Major
third
5
4
Major
seventh
15
8
Diatonic tritone
45
32
Small
limma
135
128
Imperfect third
32
27
Dominant seventh
16
9
Perfect
fourth
4
3
Octave

2
1
Perfect
fifth
3
2
Major
tone
9
8
Imperfect
sixth
27
16
False
Octave
256
135
Minor
fifth
64
45
Diatonic semitone
16
15
Minor
sixth
8
5
Minor
third
6
5
Minor
seventh
9
5
Imperfect
fourth
27
20
Diminished sixth
1024
675
Diminished third
256
225
Diminished seventh
128
75
Diminished fourth
32
25
Diminished octave
48
25
Diminished fifth
36
25
Great
limma
27
25

For every interval in Table 1, there is a symmetrically opposite interval which combines with it to make an octave. A perfect fourth and a perfect fifth combine thus to make an octave:

3/2 x 4/3 = 2/1

A major sixth and a minor third combine thus:

5/3 x 6/5 = 2/1

An augmented third and a diminished sixth combine thus:

675/512 x 1024/675 = 2/1

The table below shows these intervals as note names.


Table 2

Notes arranged by ascending or descending fifths and ascending or descending major thirds (from Longuet-Higgins, 1962a, 1987)

D# A# E# B# Fx Cx Gx Dx
B F# C# G# D# A# E# B#
G D A E B F# C# G#
Eb Bb F C G D A E
Cb Gb Db Ab Eb Bb F C
Abb Ebb Bbb Fb Cb Gb Db Ab

The boundary areas of Table 2 are used much less than the central area of the table. There is a repeating pattern and note names are repeated, that is, different notes have the same name. Musical context should make clear which note is being used, and, other things being equal, the note closest to C is to be preferred.

A third (octaves) dimension can be imagined perpendicular to the page, corresponding to pitch height.

The two-dimensional nature of hue

There have been repeated attempts to find a rational basis for linking hue with music. Sometimes attempts have been made to link the spectrum of light with the spectrum of sound. Sometimes attempts have been made to link the spectrum of light to the cycle of fifths. (This was in part Scriabin's approach (Peacock, 1985).) However hue is two- dimensional, and Longuet-Higgins's two-dimensional layout of notes provides a better foundation for a link.

The proposed match is based on the structural similarity of the rules for combining elementary colours and elementary musical intervals.

In additive colour mixing (mixing coloured lights) the primary colours are red, green and blue. They combine according to the following rules: red and green make yellow, and yellow and blue make white (or grey, depending on the brightness). Similarly a major third and a minor third make a fifth, and a fifth and a fourth make an octave. (Other musical intervals can be regarded as compounds of these primaries. For example, a major seventh is a compound of a perfect fifth and a major third, and a minor sixth is a compound of a perfect fourth and a minor third.) These rules can be represented by tree structures.


Figure 1

Tree structures showing the hierarchical pattern of the combination rules for
(a) primary coloured lights (b) primary musical intervals.


If we wish to cross match corresponding points in the two structures we have two choices. We can match a major third with red and a minor third with green, or we can match a major third with green and a minor third with red. If we match red to the major third, we can construct Table 3, in which symmetrically opposite notes are assigned colours which cancel each other out to produce white, in the same way that the intervals combine to make an octave.

For each step up from C we add red, for each step down from C we add blue-green, for each step to the left from C we add blue, and for each step to the right from C we add yellow.


Table 3

The assignment of colours to notes which results when yellow, blue, red and green are linked to the perfect fifth, perfect fourth, major third and minor third respectively.
Code: b = blue, y = yellow, r = red, g = green.

D#
3b
3r
A#
2b
3r
E#
b
3r
B#

3r
Fx
y
3r
Cx
2y
3r
Gx
3y
3r
Dx
4y
3r
B
3b
2r
F#
2b
2r
C#
b
2r
G#

2r
D#
y
2r
A#
2y
2r
E#
3y
2r
B#
4y
2r
G
3b
r
D
2b
r
A
b
r
E

r
B
y
r
F#
2y
r
C#
3y
r
G#
4y
r
Eb
3b
Bb
2b
F
b
C

G
y
D
2y
A
3y
E
4y
Cb
3b
bg
Gb
2b
bg
Db
b
bg
Ab

bg
Eb
y
bg
Bb
2y
bg
F
3y
bg
C
4y
bg
Abb
3b
2b2g
Ebb
2b
2b2g
Bbb
b
2b2g
Fb

2b2g
Cb
y
2b2g
Gb
2y
2b2g
Db
3y
2b2g
Ab
4y
2b2g

The numbers refer to the quantity of colour. Thus "2yr" for F# means 2 parts yellow, one part red.

When opposing blues and yellows assigned to a note are allowed to cancel each other out appropriately, we get Table 4. For example, for Eb the yellow and blue cancel each other out to make white, leaving the colour for Eb as green. Sharp notes are predominantly purple, red and yellow while flat notes are predominantly blue and green.


Table 4

The assignment of colours to notes which results when yellow, blue, red and green are linked to the perfect fifth, perfect fourth, major third and minor third respectively and opposing blues and yellows assigned to a note are allowed to cancel each other out.
Code: b = blue, y = yellow, r = red, g = green.
D#
3b3r
A#
2b3r
E#
b3r
B#
3r
Fx
y3r
Cx
2y3r
Gx
3y3r
Dx
4y3r
B
3b2r
F#
2b2r
C#
b2r
G#
2r
D#
y2r
A#
2y2r
E#
3y2r
B#
4y2r
G
3br
D
2br
A
br
E
r
B
yr
F#
2yr
C#
3yr
G#
4yr
Eb
3b
Bb
2b
F
b
C

G
y
D
2y
A
3y
E
4y
Cb
4bg
Gb
3bg
Db
2bg
Ab
bg
Eb
g
Bb
yg
F
2yg
C
3yg
Abb
5b2g
Ebb
4b2g
Bbb
3b2g
Fb
2b2g
Cb
b2g
Gb
2g
Db
y2g
Ab
2y2g


If green is linked to the major third and red to the minor third and opposing blues and yellows assigned to a note are allowed to cancel each other out appropriately, we get Table 5, in which sharp notes are predominantly yellow and green, and flat notes are predominantly blue and red.


Table 5

The assignment of colours to notes which results when blue, yellow, red and green are linked to the perfect fourth, perfect fifth, minor third and major third respectively, and opposing blues and yellows assigned to a note are allowed to cancel each other out.
Code: b = blue, y = yellow, r = red, g = green.
D#
3b3g
A#
2b3g
E#
b3g
B#
3g
Fx
y3g
Cx
2y3g
Gx
3y3g
Dx
4y3g
B
3b2g
F#
2b2g
C#
b2g
G#
2g
D#
y2g
A#
2y2g
E#
3y2g
B#
4y2g
G
3b g
D
2bg
A
bg
E
g
B
yg
F#
2yg
C#
3yg
G#
4yg
Eb
3b
Bb
2b
F
b
C

G
y
D
2y
A
3y
E
4y
Cb
4br
Gb
3br
Db
2br
Ab
br
Eb
r
Bb
yr
F
2yr
C
3yr
Abb
5b2r
Ebb
4b2r
Bbb
3b2r
Fb
2b2r
Cb
b2r
Gb
2r
Db
y2r
Ab
2y2r


In both tables the ring of keys around C (E B G Eb Ab Db F A) corresponds approximately to the colour circle. The difference between colours such as yellow for G and 2 x yellow for D is presumably one of greater saturation. There is evidence that supersaturated yellow is perceived as brown (Boynton, 1979).

Table 4 seems preferable to the writer as it accounts, for example, for Wagner’s choice of the key of Eb major for the Rhinegold prelude to match the green waters of the Rhine, or the intensification of excitement by the modulation from the key of C major to E major at the end of Ravel’s Bolero (white to red), or the minor third which begins Greensleaves, or the move from a cool key (Bb major - blue) to a warmer key (A major - purple) to represent sunrise in Richard Strauss's Alpine Symphony. (Of course, numerous contrary examples can be found.) Table 4 also seems intuitively preferable, as to the writer a major third sounds warmer than a minor third.

A third dimension corresponding to brightness can be imagined perpendicular to the page.

Notes an octave apart have the same hue but differ in brightness. Enharmonic equivalents such as C# and Db have different hues but the same brightness.

Table 6 below shows Table 4 as a colour display. No attempt has been made to control colour saturation or brightness.


Table 6

Fifths-thirds space interpreted as a colour display. No attempt has been made to control colour saturation or brightness.

D# A# E# B# Fx Cx Gx Dx
B F# C# G# D# A# E# B#
G D A E B F# C# G#
Eb Bb F C G D A E
Cb Gb Db Ab Eb Bb F C
Abb Ebb Bbb Fb Cb Gb Db Ab

Other Models of Musical Pitch

The theory presented here was worked out before the publication of the musical pitch models of Shepard (1982), Krumhansl (1990) and Lerdahl (2001).

All three models assume the identity of enharmonic equivalents such as F# and Gb and therefore do not lend themselves to a matching of notes and colours. All three models are concerned with relatedness in music but not with musical semantics.

Colour-Music?

The thought will probably occur to some readers that a way of testing the Table 4 and Table 5 theories would be to make animated sequences of colours to represent melodies, thus producing a visual analogue of music.

While rhythm can be represented visually, it is doubtful that the harmonic half of music can. First, since pitch height corresponds to brightness (Marks, 1974,1975) there is the problem of producing a very wide ranging grey scale. A semitone is much more than a just noticeable difference in pitch and it would be very difficult to represent, say, three octaves with 36 obviously different levels of brightness. Alternatively, but less satisfactorily, pitch height could be represented as physical height in a display, or as size (low notes bigger, high notes smaller), or as both.

Secondly and more importantly, there is almost certainly much more to the semantics of musical intervals than colour. Green may represent the subdued quality of a minor third but there is no reason to think that it represent its pathos. Blue is the colour more often associated with melancholy. Colours do not show the stability of musical intervals, or the gravitational pull the tonic exerts on the leading note.

In the writer's view, musical notes have 6 or 7 qualities:

- simple pitch height above the tonic

- hedonic quality (major/neutral/minor)

- stability

- primary vs compound

- resolves up vs resolves down

- number of semitones between a note and the note it resolves to

- colour

However, for the curious, here is one attempt to represent musical notes visually. The music is the first prelude from J. S. Bach's The Well Tempered Clavier , script by Ian Firth, and animation by the Vivid Group.

Musical Keys and Colours

Many musicians have linked musical keys to colours. From Table 6 we can read off the colour to match any keynote. The available evidence, which is largely anecdotal, indicates the everyone is different in matching keys to colours. This may be due to erroneous early learning, as key-colour associations are often formed during childhood. Or it may be due to the association of a colour with a particular composition written in a key, carried over to the key. Or it could be due to linking a change of key to a colour, rather than the new key itself.

Research is needed into how key colour associations are formed. Vernon (1930) gives a useful description of how he came to link keys to colours.

Key-colour associations are the commonest form of synaesthesia in music. This might be because a change of key has only two properties: the musical pitch difference between the old and new keys (e.g. up or down a perfect fifth), and a colour change.

Need for Data

The theory should not be accepted as true without supporting data, which may be difficult to obtain. Research carried out by the writer was inconclusive, that is, there was a trend in favour of the theory but it did not reach statistical significance. Much more research is needed.

Conclusion

The question remains of how the parallel between colours and musical intervals could arise. Most psychologists at present would probably favour an explanation in terms of the evolution of human perceptual systems. Plato might have seen in it a reflection of a non-physical reality. Taoists might see in it a complex manifestation of the cosmic forces of yin and yang (flat notes yin, sharp notes yang, cool colours yin, warm colours yang). The writer favours a cosmic rather than a neurological explanation.

Ian C. Firth, 2007
Unit 9, 52-56 Goderich Street,
East Perth WA 6004
Australia

References

Aristotle (1984). Sense and sensibilia. In The Complete Works of Aristotle, Volume 1, pp 693-713. Princeton, NJ: Princeton University Press.

Boynton, R.M. (1979). Human color vision. New York: Holt, Rinehart & Winston.

Firth, I. C. (1981). On the linkage of musical keys to colours. Speculations in Science and Technology, 4, 501 - 508.

Firth, I.C. (2005). Keys and colours in Das Rheingold. (Unpublished paper.)

Firth, I.C. (2005). Musical key perception in relation to colour. (Unpublished paper.)

Krumhansl, C. (1990). Cognitive Foundations of Musical Pitch. New York:Oxford University Press.

Lerdahl, F. (2001). Tonal Pitch Space. New York: Oxford University Press.

Longuet-Higgins, H. C. (1962a). Letter to a musical friend. Music Review, 23, 244-48.

Longuet-Higgins, H. C. (1962b). Second letter to a musical friend. Music Review, 23, 271-80.

Longuet-Higgins, H. C. (1987). Mental Processes: Studies in Cognitive Science. Cambridge, Mass.: MIT Press.

McClain, E. G. (1978). The Pythagorean Plato. Stony Brook, N. Y.: Nicolas Hays Ltd.

Marks, L. E. (1974). On associations of light and sound: the mediation of brightness, pitch and loudness. American Journal of Psychology, 87, 173-88.

Marks, L. E. (1975). On colored hearing synesthesia: cross-modal translations of sensory dimensions. Psychological Bulletin, 82(3), 303-31.

Newton, I. (1730/1952). Opticks. New York: Dover.

Peacock, K. (1985). Synaesthetic perception: Alexander Scriabin's color hearing. Music Perception, 2, 483-505.

Scholes, P. (1970). Colour and music, in The Oxford Companion to Music, pp 202-210. Oxford: Oxford University Press.

Shepard, R.N. (1982) Structural representations of musical pitch. In Diana Deutsch (ed.) The Psychology of Music, First Edition, pp 344-390. London and New York: Academic Press.

Vernon, P.E. (1930) Synaesthesia in music. Psyche, Vol 10, pp 22-40.