Basic Midi/Sonar X1 and Aria question

Folks, I have been so busy the last couple of years, that I have let my music go, and am now trying to get back into things. Recently I purchased the upgrade to GPO (I had the original GPO) and upgraded my Sonar to X1, and have a simple question.
In Sonar X1, I have two MIDI tracks. I want one to play through the Aria Player, and have it play the Steinway Classic sound. The second track I would like to be played is a Flute sound. I load them both in Aria, the piano in the first slot, and the flute in the second slot. When I play them on my keyboard, in Sonar, they both play at the same time. I have even tried having two instances of Aria, one with just the piano, and the second instance, just the flute. What am I doing wrong? I would like to record one track at a time, so I don't think I need to have my Midi controller (an antique Roland A-80) send out separate channels, because to be quite honest, I don't remember how to configure the controller to do that. And since I only wish to record one track at a time, I thought I could get away with setting the MIDI input in Sonar to Omni.
I'm sure there is an easy answer for this, but I don't know what it is. Any help/advice you might have is GREATLY appreciated, thanks so very much in advance!