Hardest: Probably the sort-of-fugal part in one of the latter movements -- I think the 3rd-to-last movement.
No no, changed my mind -- the hardest part is the opening, with those leaps.
BTW, it has a repeat, which means you always get a second chance.
I heard a story second-hand (so don't know for sure if it's true, but let's say it's true)
.....One time in a recital, the guy messed up the final leap up to the high D in that opening, but he figured, hey, it's OK, it gets repeated, and of course I'll get it on the second try. Well, he messed it up on the repeat too -- so he played it a third time.
The story ends there, so I assume he did get the high D on the third try.
Favorite part: Just about everything.
Side note: One of the movements has the marking "Durchaus leise zu halten" at the beginning. Even though I sort of knew German, I didn't stop to think what it meant; I just figured that was the name of some song (i.e. lied
) that he took the melody from. Later, I realized that it wasn't that at all -- it's a tempo indication/expressive indication, meaning "softly and slowly throughout."
But the thing is, those words "Durchaus leise zu halten" fit the melody perfectly.