>UPDATE. It appears that I found how to migrate the music from Windows 7 to Windows 10 without major time input.
>
>I found where the WMP metadata files are. They are in the folder c:\users\username\local\microsoft\media player.
>
>The Windows 7 has the metadata is the file CurrentDatabase_372.wmdb Windows 10 has the metadata in the file CurrentDatabase_400.wmdb.
>
>I tried coping the _372.wmdb from Windows 7 to Windows 10 and then copy it over the _400.wmdb. This didn't go well. WMP stopped working. So, MS$ made changes to the structure of the _400.wmdb, as compared to the Windows 7. And so far I cannot find any tool that would convert one .wmdb into another. Again, with the goal of migrating all my Music MP3s to Windows 10 Windows Media Player.
>
>If anyone has ideas, please let me know.

You've already confessed to using m$ and music in the same sentence, so I won't be harsh. You're already punished :).

The "database" you are talking about may be called so in Redmond. The rest of the world calls it a playlist. Try to save it as any decent stantard format - .m3u, .pls come to mind - and copy that, then just open it with the player on the new box. If it doesn't recognize the paths, just open the playlist with your favorite text editor (yes, it is plain text!) and just search-replace the wrong parts of the path.

Typical of m$. They turn even emails - which are always transported in plain text format, with all the possible encodings of the content, mostly base64 but the headers ALWAYS plain text, into something binary and hidden from you. And when things break, "my ~~~ database broke". Happens only with them - everybody else knows that plain text can't break.