The most beautiful, strange and unheard of thing that electronic music has made possible for us probably still is the perfect sine wave tone, which, like the perfect circle, is just too pure a thing to appear in nature.

Here, it appears in four voices in descending overtone scales, fast at first, slowing down, and then speeding up again - rising this time. After this first section of 3 minutes, the process happens again, but lasting 8 minutes, being a bit more dense and with gradual shifts of the scale fundamentals, resulting in very rich harmonies.