Missing (or Invisible) Music Files

If you still have the files in the music folder then you may be able to restore a backup of the library database that knows about them. You mentioned making a clear reinstall of Catalina. Did you backup and then restore the entire ~/Music folder, and/or any other folders that would have been referenced by your pre-reinstall library? If so then you may need to option-start-Music to connect to the restored library. If not then recovery from an iPod classic should be possible with nothing more than Finder and Music (see Recover media from an iPod - Apple Community) but if the files still exist on the computer they really only need to be imported into the current library. Don't delete anything prematurely. Work out what is stored where, and recover from the iPod if needed.

tt2

See Empty/corrupt iTunes/Music library after upgrade/crash - Apple Community.

tt2

Hi Steven Kinzler, 

Thank you for using the Apple Support Communities. 

We understand that some songs are missing from your Mac and we're happy to help.

"If a song used to appear in Music but doesn’t now, it may be because the music library was moved from the Music folder, or the song was moved from the Music folder. To make your songs appear in the Music window again, try the following:

• Locate your Music folder in the Finder, then drag it to the Music window. You see the songs in your library again. If the music library file is included, you also see playlists, song ratings, and other information you created.
• If that doesn’t work, your songs may be elsewhere on your hard disk. In the Finder, choose File > Find, then search for a song by title or artist. Or search for “MP4” to find files downloaded from the iTunes Store or “MP3” to find songs encoded in MP3 format. Drag songs (or folders containing songs) to the Music window to add the songs to Music again."

Learn how to Change where your music files are stored on Mac and how to Restore items backed up with Time Machine on Mac.

Best regards.

reinstall my files back to my Mac from an old iPod I have connected to my stereo. Unfortunately Apples does not make this process easy.

As far as moving tracks from an iPod to your computers library, Apple does not support that process at all! (Except for tracks purchased from the iTunes Store). You can try to make it work with a 3rd party tool.