Years ago I used to help my friend at his music store, usually during holiday season. I would demonstrate the early generation arrangers and organs to customers and make it a point to only use two fingers (one on each hand!).
I would first do a simple song on the keyboard, one that everybody knew. Then I would plug it into a home stereo system which we had set up, and play the same song. You could almost see the people thinking "That is so easy! I could do this! I could sound like this!" We sold a ton of PSR and PSS keyboards and Lowrey Genies that way.
Out of a perverse sense of irony I would often play "I Saw The Light" and wait for them to see the light and get their checkbooks out!
The polyphony on those first arrangers was so limited you really couldn't use that many notes at once anyway!