Why am I seeing folders with two letter names or numbers that are empty?

In my iTunes directory, there are a bunch of folders I didn't make, that have two letter names or two numbers, that are empty?

Why does some of newly added music show up in the Music main directory in Finder, and not in the iTunes media folder?

I have Keep iTunes Media folder box checked under iTunes preferences, as well as Copy to iTunes Media folder when adding to library?

Is the iTunes Media folder location supposed to be the folder that the Media folder is in? My preference is that the path is Music/iTunes/iTunes Media/music.