Do sounds conjure up colours in your imagination when you hear them? Or do colours evoke specific pitches or timbres in your “mind’s ear”? This condition, where stimulation of one of the senses leads to a sensory cognitive experience of another sense is called synesthesia (from ancient Greek ‘syn’ together + ‘aesthesis’ sensation). And its subset, the association of sounds with colours and vice versa is known chromesthesia.

It is difficult to say with any degree of certainty how common this condition is, as many individuals will not report it as they do not realize that their perceptions are different from those of everyone else. Not surprisingly, the statistics vary anywhere from 1 in 2000 to 1 in 23.

However, some associations have been determined. People with synesthesia relating to music may also have ‘perfect’ or ‘absolute’ pitch, a rare auditory phenomenon where an individual is able to correctly ‘pitch’ a musical note without the benefit of any reference tone.

Recent studies have also suggested a link with autism. From a sample study of 164 adults with a condition on the autistic spectrum and 97 adults without autism, synesthesia was diagnosed almost thrice as often in participants with autism, as those without (Professor Simon Baron-Cohen et al, Cambridge University, 2013).

The concept of “coloured hearing” has been known since antiquity; Greek philosophers even attempted to quantify the ‘colour’ (chroia, what we today know as the timbre or ‘tone colour’ of music) of music. Isaac Newton suggested that common frequencies were shared by musical tones and colour tones. In his book “Opticks”, he proposed that perceived colours were harmonically proportioned like the tones of a diatonic musical scale. Goethe made a similar assertion in his book “Theory of Colour”, as did Schopenhauer and Rudolf Steiner.

The concept has spilled into the very terminology of music. We speak of a chromatic scale or chromaticism, implying a spectrum of notes similar to a colour spectrum, and using the same root ‘khroma’ (colour) from ancient Greek. Similarly, we use the words tone colour to refer to the timbre or distinctive sound of an instrument.

In medieval India, this idea was elevated to quite a sophisticated amalgamation of art, (and even poetry) and music with the famous ‘Ragamala’ paintings, a series of illustrative paintings based on Ragamala (‘Garland of Ragas’) depicting various musical modes (‘Ragas’).

Beethoven called B minor the black key and D major orange; Schubert envisioned E minor as “a maiden robed in white with a rose-red bow on her chest”. Were they waxing eloquent or were they synaesthetes (people who experience synaesthesia)? Composers who are thought to have been synaesthetes include Franz Liszt, Nicolai Rimsky-Korsakov and Oliver Messiaen.

Although the Russian composer Alexander Scriabin (1872-1915) was heavily influenced by synesthesia, it is thought that he did not personally experience it. Unlike most synaethetic experience, his colour system follows the circle of fifths i.e. a colour assigned to a particular note or tonality which changed every five notes up the scale, and with no colour difference for a major or minor tonality of the same name. So C major and C minor would have the same colour, red. His original colour keyboard (Clavier à lumières), and an associated turntable of coloured lamps are still preserved in his Moscow apartment. The instrument played like a piano, but projected coloured light on a screen in the concert hall rather than sound. The clavier finds use in a specific composition by him, called Prometheus: The Poem of Fire (1910). Scriabin had planned a grand week-long performance of his unrealized magnum opus Mysterium which would combine music, light, scent and dance at the foothills of the Himalayas that would “bring the dissolution of our world in an armageddon of bliss, and usher in a new world”. Scriabin’s multi-media concerts paved the way for today’s rock concerts with overhead lights and pulsating strobes.

Pianist Marouan Benabdallah recently performed Scriabin’s music in Morocco, which also added colour and perfume as vital components of the experience.

The Russian composer Sergei Rachmaninov writes an interesting account in his autobiography ‘Recollections’ of a conversation he had with Scriabin and Rimsky-Korsakov about the association of colour and music. Rachmaninov was himself a sceptic. He was surprised that the other two were in agreement and he tried to point out the differences between their perceptions on the subject: while both agreed that D major was golden-brown, to Scriabin E-flat major was red-purple, and to Rimsky-Korsakov it was blue. Rimksy-Korsakov then pointed out a passage in Rachmaninov’s opera “The Miserly Knight” where the Old Baron discovers a treasure of gold: it was in D major! “Your intuition has unconsciously followed the laws whose very existence you have tried to deny”, Scriabin told Rachmaninov.

In the western art world, Wassily Kandinsky, Piet Mondrian, and Paul Klee experimented with image-music congruence in their paintings. Kandinsky compared painting to composing music:”Colour is the keyboard, the eyes are the hammers, the soul is the piano with many strings. The artist is the hand which plays, touching one key or another, to cause vibrations in the soul”. Kandinsky had the gift of ‘colour-hearing’, the ability to transfer what he heard onto the canvas. He used colour in a highly theoretical way associating tone with timbre, hue with pitch, and saturation with the volume of sound. He even claimed that when he saw colour he heard music.

And it has been a two-way street: Kandinsky, Klee and particularly Mondrian were inspirations to the early pointillist musical aesthetic of serialist composer Pierre Boulez (1925-).

Kandinsky's "Composition 8"

Perhaps we should not try too hard to create our own experience of sight and sound. Here is Kandinsky’s advice: “Lend your ears to music, open your eyes to painting, and… stop thinking! Just ask yourself whether the work has enabled you to ‘walk about’ into a hitherto unknown world. If the answer is yes, what more do you want?”

(An edited version of this article was published on 26 April 2015 in the Navhind Times Goa India)