MacOS Music app Songs, Artists and Albums missing but visible in Finder

Thanks to both responders for your tips and pointers - much appreciated.

I have been looking at the directories / files that are present on the computer that has been giving me problems.

Basically, what I have done is to open my music in finder and with the Music app running and open to the Songs list, selecting either the Artist folder or the subfolder(s) for an Artist and dragging to the Music app.

It appears that this is solving many of my problems (but a tedious manual process is looming) - just worried that I might be creating duplicate files somewhere. So far, using the advanced search in Finder, duplicates do not seem to be appearing.

Thanks - will update the outcome when I'm further into the process.

-jP

Thanks for your response.

I forgot to mention that ALL of the audio files that are present on my computer were added to my computer over the years by either purchasing from the iTunes store or by importing my personal CDs into the iTunes or Music app.

The issue that I have is that there does not appear to any pattern for what albums / songs are or are not visible in the Music app.

I have included a screenshot from the computer where my Music app is located. I used the example of the "38 Special" artist and there is no entry in my Music app.

All of these albums were present at some time in the past, but now there is a random list of artist and albums that are not present.

Would love to have a way to restore my library to a former (complete) state, but it appears that this is only possible by dragging the missing folders to the app window, correct?

Thanks again for responding!!

-jP