To get a lot of the effects you get on the demo, you will surely need an external sequencer.
One suggestion is to play the midi part of the demo on an external sequencer such as Cakewalk, and then look at the midi events to see what they did.
With Cakewalk you can paste in a fast succession of cymbal hits, you can put two cymbals on left and right channels, you can adjust the balance and volume with a stroke of the mouse.
I suspect myself that when Yamaha and other big keyboard makers create their styles and their demos that they plug midi drums, midi guitars, midi horns, midi flutes, and other midi instruments into the keyboard and go from there.

Larry