Peter M. Mahr is a musician and synthesizer enthusiast from Austria living in Switzerland. He is playing, among a lot of other synthesizers, also a C15 and did some excellent demo recordings with it. The examples below were recorded without using external effects, the sound is purely from the C15.
Being also a photographer he made a drone flight over a beautiful lake in the Swiss Alps and accompanied his shooting musically on the C15. Please find the link below.