I'm having a bit of trouble figuring out the fingering for the double trill in the finale, starting in measure 164.

The right hand fingering is pretty self-explanatory. I assume the left-hand should switch from 1b-2c# to 2b-1c#, but how to best negotiate that and where?

And then... any advice on how best to learn/practice this to gain mastery?

thanks
vince

I'm replying off of the top o' me 'ead....scoreless....so I hope that this makes sense:

IMO, the lh 12 fingering should only last for the first beat of the triplet melody (@ that low B). As you strike the first lh G-sharp then you can revert to the 21 fingering.

As far as a strategy for that section: I feel that one cannot allow the trills to sound as if they are dictating the tempo. So first I would concentrate more on the outer parts being played with a firm pulse (be it fast or slow - I would side with slow to start) while the trills themselves are played freely and a bit on the soft side (it wouldn't hurt - even at this stage - to play the trills quickly).

When you feel comfortable with this, then it's time to raise the pulse of the outer voices. The speed of the trills needn't increase at the start. If you're not forcing them, they might speed up on their own after a couple of repetitions. You should still be playing them freely until you feel that you can bring them together without disturbing the dynamic balance between the voices.

Repeat the process again until you reach the tempo of the outer voices that you want. After you get there, you need to do the necessary work to bring the trills together without sounding louder and "pulse-y" - which shouldn't be so hard if you've followed the steps as outlined above.

Please keep in mind that your teacher might have a different strategy for this, or a different opinion on how the trills should be played - one(s) that are better suited for you than mine.

Enjoy the work!

edit: Now that I think of it, I believe that the Henle edition contains a pragmatic solution to your lh fingering dilemma...anyone?

Great, thanks for the tips. I'll give it a go. My biggest problem is that I find it hard to separate the pulse from the trill in the left hand. The thumb on the c# makes it more difficult because it forces my hand position to turn in at an awkward angle. I have the henle, and it gives me 12 on the first triplet to 3121, which doesn't exactly flow naturally for me even at a slow speed. But seems like there's no other option.

I don't have a teacher, so I'm kind of feeling it out myself. I've love to get one, but I have a busy day job and practice habits that are much more erratic than I like. I'll be on the road for weeks and unable to get a practice in, and then gorge for 6 hours a day during thanksgiving.