Experimental track produced with sounds created in Mammut, free FFT software from Norway.
Inspired in part by an acephalgic migraine I experienced recently / scintillating scotoma (an optical distortion in perception which - in this case happily was not followed by the headache)
Wrote about the tool, too (early 21st century software!):
http://cdm.link/2018/02/mammut-free-software-completely-insane-things-sounds/