After discovering I didn't have to use iTunes to play music on Apple I very eagerly created my ID last night. I played music through the web interface for about four hours without any difficulty. As a person who is blind, using the computer by means of screen reading software, I found the interface to be very accessible. Even the time slider, which are usually problematic.
Unlike ambush66, the slow responses didn't bother me. In fact the lengthy pauses between songs quite suits my purpose...
Now, I consistently get the error message as per subject; logging out and back in does not help.
I am keen to be able to access Apple Music, because I understand it contains a lot more original recordings than other services. Heck, I even found barbershop harmony albums.