Mozart may be the most difficult of all composers in that it is so easy to make his music sound perfect, pretty, predictable -- in other words, utterly beside any meaningful point.
This week I am performing a work that has utterly mystified me for most of my adult life. The A Minor Rondo, K. 511 is so dramatic that it cannot be pinned down to a particular moment as the right one, or to a particular reading as definitive. It has to be recreated afresh every time it is played. Perhaps that is the reason for it's being in the first place: in a rondo the material "repeats" so often it has to be dealt with as new every time.
This is harder than anything one is trained to expect from music of any period, least of all the 18th century.