I’m fairly certain that Leonard Bernstein was under the influence of something when he wrote out the piano part to West Side Story. (To be fair, according to wikipedia he had assistants, so maybe it was one of them.) In the prologue, there is a piano solo. A solo which the orchestra director has assured me is really, truly necessary. The prologue is played at approximately 120 bpm. In the space of 4 beats (2 seconds) I have to play a B-flat major run up three scales, plus a few half steps at the end. So I literally have to play 7 notes in a half a second three times in a row, and then 6 more notes in a half a second.
I have practiced this 2 second snippet of music for hours so far, and the best I can do is about half-tempo – and that’s with plenty of mistakes. I think I need to hire a stunt double!