Thanks Mike ... I have been doing a lot of trial and error processing of Midi tracks and while doing so, I am learning bit by bit.   I've been importing Midi Tracks and having them all outputted to the CW  TTS-1 Synth.  That process seems restrictive so I just tried doing what another suggested i.e.; creating a CW TTS-1 synth for each track and then assigning an instrument.  So far this seems like the better way and the instrument, it seems,  doesn't revert to (say) piano  when the track is re-started. I'm getting there and enjoying the experience.  
 
I just watched a video on Cakewalk University (I think it is called) and watched a couple of dudes creating a composition including synth instruments. live guitar and  synth drums.  I was taken by the idea of using the Matrix View to mix and match various instruments while arranging a track. At least I think that was what I saw!  I need to look into that  idea more.  Does it ever end???  The flexibility of Sonar is remarkable.