I’ve been tinkering with Plex again, and I wanted to add my iTunes music library. Unfortunately, iTunes nests Movies and TV Shows inside of the general music folder, and I had already added those folders as Music and TV Shows libraries in Plex. A little digging turned up the documentation for .plexignore files.

I created a file named ~/Music/iTunes/iTunes Music/.plexignore:

# Ignore Movies
Movies/*

# Ignore TV Shows
TV Shows/*

And I then added ~/Music/iTunes/iTunes Music/ as a Music library in Plex. That seems to have done the trick; the music is now available via Plex without duplication of the movies and TV shows.