I just bought a new sax for my daughter. I played when I was in school but that was a long time ago. Anyway, on the back of the sax towards the top is a round black plastic cap looking thing. Does that cap come off or stay on? I said it was a stupid question.

Thank you for your help

At the top of the sax is a plastic cap that protects your octive key that stays on only when the instrument is stored. The only other thing I can think of is the plastic/rubber piece at the top of the octive key, do not take that off.

Hope this is your issue
CJ

Thank you very much. I think it is the cap. It just does not want to come off easily at all. I'm afraid of hurting the sax in some way.

That's your thumb rest, stop trying to pry it off.

LOL I will stop trying to pry it off. It is the thumb rest. Sorry to be so dumb. But thank you all for your help.