Some of us older people might enjoy this virtual interactive GUI of the Mighty Wuritzer. http://www.virtualorgan.com/Default.asp?Page=72
Follow the link, then go to getting started to download free. It immediately plays with computer mouse, but the real fun starts when you connect midi keyboards to it.
I have channel one(solo),attached now with a little Oxygen8 controller. I will put another on ch2(accompiniment), and ch3(bass pedals).
It is all rather amazing,
pa4X 76 ,SX900, Audya 76,Yamaha S970 , vArranger, Hammond SK1, Ketron SD40, Centerpoint Space Station, Bose compact