We are going to use these shortcuts:

1. Highlight a track that you want to turn to a harmony track:

2. Press Ctrl-Shift-H:

This will add "Join Notes" and "Tranpose" variations to the track. Open the track inspector by right clicking on the track header:

You can disable joining notes at chord boundaries. You will get this:

Let's check what happens with the chords when the master track changes for any reason. Drag a chord progression to the master track to replace the whole progression for Line 1:

It works
