Why are there two complete Music folders on my system?

If I use Show in Finder in Music it takes me to a track that's located here

~/Music/Media/Music/Artist/Album/Track

There's an actual file there.

In ~/Music there is another whole set of this media. It's located in ~/Music/ Music where there is the complete array of artist folders with album folders and tracks. The tracks are the actual media. There are no symlinks in either location. What's the purpose of the two folders? Is the second folder obsolete? Can it be trashed? Why is is there in the first place? Or is it just a residue of the older iTunes system?

The first Music folder is 31.19GB, while the second Music folder is 30.87GB. So not identical. This makes me think is first is more recently updated with newer content that isn't in the second Music folder.

Can anybody tell me why this has happened?

Also, what is the purpose of the item ~/Music/Music Library. It's not actually a library in the same way as Photos Library, whose container holds the physical images. What's it do? The largest item in seems to be a Genius database. What's the point of that Music Library? The whole ~/Music looks like a bit of a dumpster dive.

Really wish some Music app expert could explain this to me.

Thank you very much.