Only half of iTunes has synced

I installed Audirvana on my Mac Mini (2014) running Catalina 10.15.5. Using “First method: Monitored folders”, I find that Audirvana has synced 3,948 albums, vs. iTunes (“Music” in OSX-speak) which shows 5,940 albums.

Why the difference?

Hello @glennramsdell, what is the format of the missing files? Are they m4p files?