Hi Ted,
To do what you are suggesting, if I understand it correctly, you would have to erase track 4 to erase the chord structure, and then all the other tracks, which are recorded in sink with the recorded song. If you left only the panel memories, you would have most of the registrations, but not all.
In my sequencing activities, I frequently work on a song part using several tracks at one time in order to get the kind of sound, ensemble, etc., that I desire and of course also change the rhythm pattern at the same time.
You could certainly play along then with the result but I think the result would be almost a blank song, or close to it.
It's possible that I might have misunderstood your suggestion.
Thanks,
Larry