Hello,
I just went through the same thing. The support doc (Switch libraries with the Apple Music app in macOS - Apple Support
) should work but it doesn't. I called Apple support and after 10 days of trying, I realized that most of them are... ahem .. less than helpful. From "Apple music doesn't play local files" to "you must have apple music", the answers were terrible. But in the midst of that mess, one senior tech mentioned that it would only work using migration assistant. I did not want to use MA, but I thought of this workaround, hopefully, it will help:
My conditions to be able to use Migration Assistance:
- I already had copied my music folder to my new mac. Including my music. This is where the steps delineated above should work but they do not.
- I have access to my old mac, hopefully, you do too. But this method should work with a time machine backup.
My very complicated steps to minimize file copying time.
- I created a new user on the OLD mac. In it, I copied just the library itl file. I did the OPTION+click and open my library on the new user in the OLD mac. It won't be able to find the media, but don't worry about it. You'll see all your playlists, that's what matters.
- I started Migration assistant on both computers. I made sure to only transfer the new user from the OLD mac. I did not transferred anything else. The NEW machine will ask if you want to delete your current profile on the NEW mac, be careful, but it will let you import the new user and keep your current profile.
- In this case, Migration assistance will convert the library, and when you log in to the account of the new user on the NEW mac, you'll see the updated library (again you won't see the media, but that is OK). Copy the new itl file from Apple Music to a shared folder or thumb drive so you can transfer it to your current user on the NEW mac.
- On your current profile, replace the old library with the new one. Now make sure your media is organized in the new style structure. That is easy though, just place all your actual music in the ..usr/Music/Music/Media/Music folder.
- In my case, because I kept the original name of the ITL file, when I opened the music app, it was able to pick up the updated library and show everything working. If it has another name, choose it using the OPTION+click method from above.
Good luck, it is a pity no one at Apple seems to know a better shortcut. Let me know how it goes, I'll try to help if I can.
EDIT: I still have to figure out how to make Apple Music "scan" the media so it loads its album covers and other info, but one problem at a time!