Nice tip!! Freezing tracks is a cool feature I use a lot since it was implemented in Band-in-a-Box some years ago.

Here an additional little "service" trick around this tip: in the case when I need go back to the original progression after freeze or have extra or modified chord progressions at hand, I use the 'not played chord area' (the unused chord area after song END ) as a "chord scratch pad". That way I avoid having to re-type enter it again, save and reload again the song or write the chord progression manually out of BIAB.

- Just copy and paste in the unused chord area the chord(s) or chord progression that you want to keep for later recover. You can even include your bar settings: pushes, shot, hold chords, rest, as Icelander point in his excellent Tip. Sometimes I have several saved progressions there.

Of course, this is useful as long as that area have bars available, which is quite likely happens most of time. So, If your song is very long then you can run out of space for this workaround.




NOTE:
I don't know if it has already been posted, but it may be useful to those who have not seen it before. Please, let me know if not, to post it apart.