Hi RANKINMIKEE!
So I was on with a really helpful Apple support agent (Vicky) yesterday (March 18, 2020) with similar problems to yours with the app formerly known as iTunes. Since upgrading to a new 16" MacBook Pro (fully maxed out spec) running Catalina, the new "Music" app has rather irritatingly "lost" all the album artwork I had painstakingly added (since 2009) to my own ripped albums, not to mention all the artwork and metadata I had added to all the DVD's I ripped to my collection. Sure the actual music and video is still there - just sans artwork.
As I explained to Vicky, all my music and films are stored on a completely separate 4TB HDD. The issues that I have faced since January are this:
1 - missing artwork - as listed above.
2 - unable to download artwork using the built in function in music.
3 - unable to manually add the artwork (having gone to discogs or other such site, saving image to desktop and then dragging/copying pasting to the Album/Song Information window/Artwork tab. Yes it allows me paste it... but it doesn't make it "stick".
4 - unable to manually add/change the names of tracks for albums that I've ripped that are old and don't have the track listings on grace note.
5 - In album view or Recently Added, I like to list my albums that have multiple disks under ONE album - not 2 or more separate albums. If I go into the Album Info window and delete the XXXXX (Disk 1) from the album name for the entire group of that album it then separates out into more albums based on artists and or performers. AND magically gets rid of the artwork.
6 - unable to change the genre of albums
7 - after I decide to pack it all in for the day and just close iTunes (Music) and eject the external music drive... It closes the app but does NOT eject the disk. Says "Disk still in use. Force Eject." Even though nothing is using it.
Vicky (the Apple tech) was helpful but admitted this all of these were known issues and their coders are working on a fix for the next update. I asked her if there was a place I could go to give feedback and she gave me this address: ****
It doesn't work.
SO... My work arounds have been as follows. Downloaded and installed a cross platform freeware tagger called MusicBrainz Picard which definitely works but is a learning curve. There are helpful tutorials on YouTube. Sometimes this works while the Music (iTunes) app is running and sometimes it doesn't. In the last few days of futzing around with it I have found that the only way to add the correct tags and artwork is to use the MusicBrainz Picard to update the album tags for your albums. THEN open Music:
Select the album - delete the album (but keep files - do not send to trash) then go to File - Add/Import Album - (locate Album) and then import it back in - and this time it loads the artwork. The only downside is you have to do this for ALL your albums and songs. If you have a vast library like I do... then this is not a fast and easy fix.
Our best bet is to wait and hope that Apple has their developers working to make this app as great as it once was (and it wasn't perfect then). Fingers crossed, but NOT holding my breath.
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