I guess I must have missed something here. There is an onboard program in all Yamaha arrangers since the PSR-2000 called Style Creator. Yes, you modify a style using it, or just use the onboard drum kits, voices, etc.. and create your own style from scratch. It's not difficult, but it does take a bit of timing, chops and skill to create a good style. To create an outstanding style you need to be creative, skilled and have lots of free time to work on the style.

Gary