Thank you Salsaman, no multi-tracking or over dubbing, just sit and play. The organ was part of the style. The Ketron is probably the most live-sounding of all arrangers.
Edit:
Actually, I listened to that song again, and in part of it I was using the Riff feature. The fourth variation on the style has built-in comping, along with a chord progression. That's probably the organ you were referring to.