iTunes 12.7 how to download all music from iTunes Match Mac OS 10.13.4, iTunes 12.7.4

Somehow my music library has become screwed up, and almost all of my 28,000-odd tracks aren't where they should be (according to iTunes). I can create a playlist of all the tracks, and I can export that playlist to a text file. But I don't see how to download those tracks to a library.

All of this happened following moving my Film library to an external drive, tho I don't see the connection. My TV Programs appear to be Ok.

Help!!
If you need to download the already uploaded music to the iCloud (iTunes Match), you could try re-syncing the media library.


Step1 : sign out from iTunes 
Step 2 : Delete all the remaining music files.
Step 3 : Sign in to the iTunes.
Step 4 : Let it to sync the music library from iCloud.

For more info : https://discussions.apple.com/thread/8046575