Last night I decided to "refresh" the music I have stored on my phone. During this process I noticed something that I can't figure out, so thought I'd see if it rings a bell for anyone...
1. In Windows 10 File Explorer I can navigate to the folder on my desktop where all my music is stored, something like C:\Music\iTunes\iTunes Media\Music.
2. Under this there are separate folders for each artist, e.g. C:\Music\iTunes\iTunes Media\Music\Soundgarden.
3. Under these are folders for each album by the artist, e.g. C:\Music\iTunes\iTunes Media\Music\Soundgarden\Superunknown.
4. Within these folders are the files for each track on the album, e.g. C:\Music\iTunes\iTunes Media\Music\Soundgarden\Superunknown\03 Fell On Black Days.mp3.
I can find every track on every album by every artist in my iTunes library this way and copy what I want to my phone, but it's time consuming as I have to go up and down one or two directory levels each time I want to select tracks from a different album or artist.
I thought I could save time by selecting the whole music library at C:\Music\iTunes\iTunes Media\Music level and searching for everything under this folder using the *.* wildcard search string. I could then sort the resulting list by artist, album, etc. and select what I want from a single list. But I noticed that some whole albums/folders don't show up in the list of files when I do this. They are definitely there when I drill down using steps 1,2,3 above, but are not showing in the results when I do the wildcard search - I can't see the album/folder name or any of the tracks in the list of files.
I've only noticed three albums missing so far, but as I have around 1000 albums I haven't been through the entire list (yet). So far the missing albums are all ones that would have been imported by iTunes from CDs I own (not music purchased/downloaded from the iTunes store) however there are hundreds of albums that do show in the list that were imported before and after the missing ones, so not sure what makes these few albums "special".
Any ideas what might cause something like this - certain "random" folders/files not showing in the search results?

) - just using that as an example of one I saw was was missing once I'd noticed the problem, as it should have been right at the top of the list when sorted by artist.