Personally , I have played the the op. 13 23 24(sonata for violin and piano) and 58(concerto 4) entirely . Now I am about to play my first Beethoven's late sonata,op.111.
My teacher tells me that technically , op.111 is the same level of 4th concerto , but still , I will encounter difficulty for sure because it is Late sonatas...
Before I enter the conservatory , I also played some movements of some his sonatas, like moonlight ,appassionata ,op.2 no.1... I think that I am totally prepared to start the next phase. But why is my teacher so sure about it will still be difficult for me, I do not quite believe it.
In a other word, what should I pay attention to when I work at it?