First thing I noticed were many new exclamation points indicating missing tracks. These apparently were moved to Users/Shared/Relocated Items as they had been “in a location that is now incompatible with macOS security settings.” Music seemed to find them when I attempted to play these tracks.
Disclosure 1: Many of my iTunes tracks have resided in various Unix linked directories since I ran out of local hard drive space back around version 5. They are still strewn about more that I like. I never could seem to get then all into Music/iTunes/iTunes/ Media/Music, many of them preferring to remain in Music/iTunes/iTunes Music.
Next were my chosen column headers which I mostly resurrected.
And finally there was the missing artwork and Music’s incessant “loading artwork” and memory issues.
Disclosure 2: I have 22,880 albums and many didn’t have artwork previously (e.g., SXSW 2006 Showcasing Artist).
The artwork has indeed been loading to /Users/<my-name>/Library/Containers/com.apple.AMPArtworkAgent/Data/Documents/artwork, but at a snail’s pace. Sometime shortly after the foolish click on the Catalina upgrade I had 7,640 items in that artwork folder. After stopping and starting Music intermittently over the past few weeks, that folder has 7,707 items (sizes varying from 406 bytes to 15.5 MB.) I would daresay Music has been open for somewhere nearing a hundred hours during that time. Sleep may have overcome the process….
That memory issue is the kicker since Music occasionally crashes and, I assume, loses the work it was performing. In Activity Monitor, choose View->Inspect Process and select Open Files and Ports shows a bunch of .itc files located in /Users/<my-name>/Music/iTunes/Album Artwork/Download/. According to https://fileinfo.com/extension/itc these files were part of cover flow (gone since version 11.) One might think that there’s some artwork loading involving those files but….
I haven’t tried Dougs scripts but once it rains (tomorrow) maybe I’ll get a chance.