This is programmed music. It is software. So it's all code, inluding the instruments.
Don used fractal data in a Midii program to sequence (i.e.,compose) the music.
Midi is a technology pionered by Microsoft and used for Window's Quicktime. It has been
ported over to the Mac, but not for Mojave or Catalina and probably future operating systems.
It does not play in those systems.