Brain waves and sound waves
I approached a physician acquaintance of mine with a request to play the Threnody to a psychiatric patient in a clinic and study his EEG. First we looked at his normal graph, then at one while he was listening to my music, which was quite different. The piece made an impression on him. He said he’s never heard anything similar. I translated that EEG into a music score and this is how Polymorphia was born. --- Krzysztof Penderecki, The Family Saga, p. 281.