Dreaming in waves of cascading colour

I've taken to quick naps in the afternoon of late (gramps that I am), and today I was dozing whilst listening to the Proms on BBC Radio 3. A young Chinese pianist, called Lang Lang, was performing Chopin's Piano Concerto No. 1 in E Minor, and suddenly my inner eye was seeing all these cascading sheets of colour, following the music, falling vertically and waving horizontally, and seeming to send a surge of energy coursing through my whole body. I was in a half sleep, not quite awake but not quite asleep, and I tell you, I rode that incredible experience all the way to the end of the piece. As soon as it finished, my eyes snapped open and I was wide awake, glowing and fully rested.