Thanks for the information, pbghmike. You're modest.
I hadn't intended to single out anyone in particular, but,
rather, to illustrate the point. If I were to list the exceptional
talents associated with this forum, I'd still be writing.
The topic has had the effect of stimulating thought on
my part. Probably shouldn't go there, but, "How the heck
does Band-in-a-Box work, anyway?" The video that shows
how the same progressions may create different songs
provides a clue, not the whole answer. I find, sometimes,
renderings seem to contain the melody, with no
explanation as to how that could be. It's like they
have some weird Ai in a cage, somewhere.

Link: www.soundcloud.com/ed_shaw (Feel Free to Use)
https://drooble.com/edward.shaw/hymn/index.htm
Biab for WIN 2020 -- Win 10 64bit -- Reaper/Audacity
Zoom R-16 -- Tascam DP-03-SD -- SoundTap -- Crescendo --