Hi again,
The more I look into this the more screw-ups I discover. One problem is that I don't know how the new folders and files are organized. I still have the old iTunes folder with all the regular files in them but when I pointed Music app to that (as suggested which at least seemed to solve some of the problems), it asked me to create a Music folder, which I could name and specify the location for. It's for now residing outside the old iTunes folder. So what folders and files are superfluous? Where should the Album Artwork folder be? At what level should the Music Library.musiclibrary be? In iTunes Media which was created in the old iTunes folder? Is there a chart for the proper nesting of all the folders and files under Catalina? I don't want to carry duplicate files or orphaned files around. My iTunes folder was 180 GB at some point so I don't want to inflate this with unnecessary outdated or even disruptive old files that also take up space.
The problems I am still having:
(1) I have all previous Playlist Folders and Playlists in Music now but not all Artwork was transferred but others have (not dependent on whether it was a commercially purchased CD, bought from Apple, or home-made including artwork. In all categories some artwork is there and in others it's not). I really see no systematic pattern here.
(2) I have all previous Playlist Folders and Playlists in Music now but some Playlists (stand alone or in Playlist Folders) only have the shell but no songs included. So it looks the same as it used to be but lots of actual songs are missing in the Playlists or Playlists embedded in Playlist Folders, even though it appears that all the files are still somewhere in Library (but a nightmare to recreate all the organization I had from so many years).
(3) I would like to go back to the pre-Catalina OS but Time Machine won't let me do this. I thought I was acting cautiously and responsibly for having backed up everything before the attempted switch to Catalina but now I am really in bad shape because I can't go back but I also cannot make Catalina work properly. Some commercially bought software is not even available yet for Catalina which puts me in a bad situation too. This switch to Catalina has resulted in a huge loss of productivity for me.
When I call 800-Apple tech support, I will be charged for service calls which I find unfair. I have bought all my software and music responsibly and legally, so I think it would be Apple's responsibility to make sure that customers get a smooth transition to a fundamentally OS if Apple decides to make drastic changes perhaps prematurely before things were tested out sufficiently. At the very least I would have appreciated a fair warning. The synching between Mac OS, iPhone, and iPad worked perfectly well before. I wouldn't have switched.
I have been using Mac since 1984 and have been a very loyal Apple fan ever since. But now I start considering of switching to an alternative platform with less monopoly ambitions and go back to user-friendliness which was the biggest selling point for Apple initially. We were proud not to have to travel with our private computer technician just to use a laptop computer. Now it seems that Apple has switched sides. Very disappointing.