It can be said that this excerpt is an approach to the "forbidden door". it seems that the reader gets in the mood by reading this description.
The paragraph is full of vivid ideas which makes it simple to picture what is happening and how this person is feeling when listening to that tapping,
I and III i am pretty sure that is right
Classical musicians require the best effort because they have to face two difficult tasks. One thing is the terror of the audition which means that you are nervous in an audition and another thing is the audition which is itself difficult.