However, if you have the entire movement memorized, perhaps nothing would come as a surprise; you would presumably be expecting everything that occurs!
Or would you?
I discuss the "Waldstein" sonata every year when I teach musical form, and every time I hear it, I am delighted/excited/amazed, and yes, even surprised, when we reach the recapitulation. Without getting too specific,1 Beethoven does some absolutely outrageous things during the recapitulation, and even though I know what's coming, it doesn't temper my visceral reaction of surprise when they happen.
Why is that?
It could be because I am slow of mind, incapable of remembering what's coming next. I won't deny this, but, even if true, I think there may be another explanation as well, and it has to do with dropping a heavy object on my toe last summer.
Here's what happened: I was helping one of my kids assemble an office chair in his room, and an extremely heavy part (the pneumatic gas cylinder, which is central metal post upon which the chair rests) fell about four feet onto my foot. I remember that the pain was about as extreme as anything I had ever felt, but I don't remember the pain itself. Put another way, I remember that something really painful happened, and I remember the cause, but I cannot recreate the visceral quality of the experience itself, unless I were to drop something heavy on my toe again. I do not plan on doing this, although life being what it is, I'm sure something similar will occur at some point in the future… :(
Here's another analogy, this time involving no pain: There are some roller-coasters that I have ridden so many times that I know in advance what to expect, and yet they thrill me every time.
Remembering an emotional response is not the same as experiencing it. When I hear the first movement of the "Waldstein" sonata, I know what is coming next. I also know that in previous hearings I was astonished at various points in the piece by the ways in which Beethoven plays with our expectations, but this knowledge does not prevent my experiencing a similar level of astonishment — I can't believe he just did that! AGAIN! — every time I hear this composition.
This strikes me as one measure of a work's greatness; it can astonish, surprise, delight, or otherwise move you every time you hear it, even if you know what is coming next.
For composers, this is extremely valuable information! If we find ways to engage our listeners and play with their expectations, there's a chance our music will continue to have a similar effect on people for a very long time to come.
If you'd like to listen to the entire first movement of the "Waldstein" sonata, here's a video with scrolling score:
1. I often ask students to identify the various unexpected/surprising things that occur during the recapitulation of this sonata, which is why I am not being more specific about what they are. I don't want to give too much away in this blog entry, because I would like students to discover these wonderful moments for themselves.↩