Bill, it's actually not all that difficult using Yamaha's onboard Style Creator program, which is found on nearly all PSR and Tyros series boards. However, these days, making a style from scratch is insane when you can find more than 50,000 great styles at the PSR-Tutorial site alone. Find an onboard style that's relatively close to what you wish, then go to work using Style Creator, create your own intro, ending, and fills, change the instruments, do any of those, things, and within an hour, you can have the most fantastic style you wish. However, there is a learning curve, just like anything else that demands creativity and hard work, and that curve, sometimes can be quite steep. Fortunately, at the PSR-Tutorial site there are dozens of great instructions to make that curve a lot easier to learn.

Not sure about the other brands of keyboards, but Yamaha, at least for me, has made this an easy task,

Gary