Comment by tgv

If you like that kind of thing: manufacturers used to create demo songs for synth keyboards and modules:

* Emu Proteus 1: https://www.youtube.com/watch?v=K5FffG_0sqw

* Emu Proteus 2: https://www.youtube.com/watch?v=O4KW9uWCY3A

* Roland MT-32: https://www.youtube.com/watch?v=jdSKg5G9MPc&t=22s

* Roland D-10: https://www.youtube.com/watch?v=zXGdyp7Ml-Y

* Roland SC-33: https://www.youtube.com/watch?v=as_jVNIvleI (complete with MIDI animation)

* Yamaha MU100: https://www.youtube.com/watch?v=6BL_RzeWDxg (1 hour!)

Etc. Don't know if they still do, but it was a thing when these "romplers" came on the market.