Synchronize songs within the music app (Mac) and the files in the music folder

How do I connect the songs within the music app (Mac) with the files in the music folder which I have copied from my former Mac to my new Mac for which I performed a clean install.

Only the files which I have imported after the transfer I can access by command-shift-R and a finder window opens with path ~/music/music/artist/album/

For all the existing files which I have manually copied by rsync from former Mac to new Mac there is no connector when I press command-shift-R although those files have been formerly synchronized with Music.

If your idea is: delete music files within ~/music/music/ thereafter download music files in Music App from Music >>> no thanks. I want to connect existing files with the music library without importing 30,000 files via Music App because this would destroy the statistics (how often played, etc.) and would completely renew my Music account which I don't want at all.

I hope at least one of you can give a solution.