twocats I think the reason she wants you to play CBCB is that your score is incorrectly marked.
I have the urtext in my lap right now. When I challenged my teacher on this point and said, “So if the short squiggle has a line through it, it’s a mordant, but if there’s no line through it, it’s a trill, right?” And she said, annoyed, “No, it’s also a mordant.” In the urtext in my lap, it says I should actually play the trill cbcbcb. So, in my opinion, this falls into the category that it’s better to be wise than right. She must have her reasons for saying what she’s saying, and I’ve decided not to use more of my lesson time trying to be right. I’m not afraid of having to rework the piece when it’s time to record, and I’ll record it how I like. I’ve heard the arguments that say if I play through even once incorrectly that it’s the end of the world, but it hasn’t been the end of the world so far. I have, in fact, been able to make changes to pieces that I have practiced a hundred times. It just takes time and grit. I will, however, ask her about the fingering for her requested cbcb. That I’m willing to do.
It takes two to make a peaceful relationship, so I pick my battles. I like my teacher and don’t have a problem quietly agreeing to disagree on one small point.