synaesthesia

Kandinsky discovered his synaesthesia at a performance of Wagner's opera Lohengrin in Moscow: "I saw all my colours in spirit, before my eyes. Wild, almost crazy lines were sketched in front of me." In 1911, after studying and settling in Germany, he was similarly moved by a Schoenberg concert and finished painting Impression III (Konzert) two days later. The abstract artist and the atonal composer became friends, and Kandinsky even exhibited Schoenberg's paintings in the first Blue Rider exhibition in Munich in the same year.

If Kandinsky had a favourite colour, it must have been blue: "The deeper the blue becomes, the more strongly it calls man towards the infinite, awakening in him a desire for the pure and, finally, for the supernatural… The brighter it becomes, the more it loses its sound, until it turns into silent stillness and becomes white." Despite his theories that the universe was in thrall to supernatural vibrations, auras and "thought-forms", many of which came from arcane, quasi-religious movements such as theosophy, Kandinsky's belief in the emotional potential of art is still convincing today. Our response to his work should mirror our appreciation of music and should come from within, not from its likenesses to the visible world: "Colour is the keyboard. The eye is the hammer. The soul is the piano with its many strings."

http://www.telegraph.co.uk/culture/art/3653012/The-man-who-heard-his-paintbox-hiss.html