People often ask me (because they know I'm, if I do say so myself, quite good at piano), whether there comes a point where a pianist's technique is sufficient enough for them to be able to practice a piece (like La Campanella say) and as long as they just practice, practice, practice, they'll be able to play it. For example, someone came up to me with a technique sufficient enough to play Rachmaninoff's prelude in G minor and Moment Musical No.4 and asked whether they would be able to learn La Campanella if they just practiced long enough. I told them it was not going to be the best idea to do this but theoretically, yes, they were at a level were if they just persisted (perhaps for more than a year or 2) they would be able to play it. I think I am right in saying this but what do other people (who maybe have some experience endlessly practicing a piece far, far greater in difficulty than anything they had every played before) think?