Interesting. I added Gunther Schuller’s ‘Concerto da Camera’ to a playlist in the Apple Classical app. Later I reopened the app and attempted to reorder the playlist and I got this error message.
I’m guessing that Apple has split their music catalog into “Classical” and “Non-Classical” sections. I don’t want to complain too much because I listen to the app all the time and generally like it.
Apologize in advance if a little off-topic.

