I used Comp recording mode to create a midi comp track.  So the track has about 20 small midi clips.  I flattened to a comp take.  That worked ok (the first time anyway).  Then I wanted to change the first 12 bars so I recorded another 6 takes over that region.  I cut the takes into 2 clips and isolated the ones I wanted.  Ok.  So the comp sounds great at the track level.
 
So I try to flatten to another comp take.  No workie.  The resultant (2nd) comp take lane doesn't even have a clip in it.  Nada.  No midi notes.  No output.   I spend an hour playing with stuff trying to get this to work.  No way, Jose.
 
So I create another instrument track with a different soft synth.  I ctrl+shift+click/drag the first tracks composite midi content down to the new instrument track.  OK.  Now I have the midi notes I want in one track, without all the "fragile-ness" of the multiple takes and comp stuff.
 
BUT I have 20 separate midi clips in my new instrument track.  I want one.
 
How can I combine multiple midi clips in a track into one clip?  (They are adjacent and contiguous.)
 
(Bounce to Clip(s) isn't enabled when I have all the clips selected...)
 
Thanks!
Keith
 

You'll need to unlock the first flattened comp in order to include it in the second, and I'm guessing the same thing is stopping you from bouncing to clips in the copied track.

Clip lock was the problem.  Thanks!
 
So the new comp take lane is locked.  I need to do some piano roll work to tighten things up.  Is it "best practice" to unlock the comp take lane and party on those midi notes?  Or copy the clip to a new track and edit that copy?  (I'm just never sure about the comp track.  Lots of moving parts with all the take lanes, mute/solo rules, locked takes, etc.  Plus it seems really easy to accidentally isolate an unwanted clip and hence "mysteriously" lose a lot of work.)
 
Suggestions?
 
Thanks
Keith
 

I see no problem with editing the flattened comp. You can always mute that lane, unmute the originals and flatten a new comp if you decide to start over. The only thing is that you may find it hard to hide notes of other lanes in the PRV without messing up your comping (since only muted clips can be hidden in the PRV). So you would probably do best to move/copy it to another track.
 
Personally I don't find that comping works well for MIDI for various reasons - not SONAR's fault for the most part, just the nature of MIDI. I prefer to get a take that's 90% good, and fix the few problems by a combination of editing and copy-pasting from other takes into the lane with the good take as opposed to comping pieces of different lanes.