It is nerve racking to compete head to head. In sports this is a fairly normal part of the job, but when it comes to artists, especially pianists, it is a big shift from the norm.
A musician's routine is quiet and predicable. You generally practice alone and it is here that you polish and learn, working on your fingering, phrasing and the little things that mean so much to you, but might not be even noticed by an audience.
