Last summer I played Keyboard 2 for a show. It was a charitable event. All performers and musicians were volunteers.
The part required keyboard splits. Using my Yamaha NP30 (a mere 12 pounds) and my Ketron SD2 I was not able to figure out how to do keyboard splits with any of my existing software.
Since I was doing this as a volunteer I didn't especially want to purchase a real midi controller. I thought surely there must be some software that would allow keyboard splits and let me save registrations for quick changes during a show.
After months of searching I have finally found it. Control Phreak, an older procuct by Florida Music Company, is exactly what I wanted.
So, if anyone else want to do keyboard splits and layers with your SD2 (or another hardware module) with a midi keyboard, not necessarily a controller with layer and split capacity built in, here's the link.
http://www.floridamusicco.com/proddetail.asp?prod=cp&partner=smm