He [Alexander Scriabin] asserted that someone listening to music was inevitably affected by the surroundings in which the music was played – that the effects of music heard in darkness were quite different from those of music heard in light, and that one’s sensations responded to variations in color just as to changes in temperature. He invited me to his house in Moscow and showed me an apparatus he had developed for reproducing sound in color. I think I must have been one of the first to see it. It was really remarkable and produced marvellous effects. He was composing a new orchestral work, Prometheus, for which he was writing a part for a keyboard of lights, so that various colors could play on a screen while the work was performed. It was the first time that anything like this had been done.