Tony, try this shortcut:
- Go to Ludwig’s composer page, then click on the Performer button. Scroll down and click “Select All Tracks”. The track list that results all have “Beethoven” as a Performer; in my experience, it is almost always a Primary Artist tag.
- Select All Tracks (cmd A) and Edit/Edit Credits/Remove Credits. Scroll until you find the Beethoven-Primary Artist tag(s) and delete it(them).
- Take some care here! If appropriate, Add a credit for Ludwig van Beethoven as Composer before you save.
This works for “quite a few” tracks at once. However, I tried it on a 1000-track list once and was denied; I asked but never found out what the upper limit might be.