Bach Sinfonia 1: Sliding (gliding) thumb legato

[gustaaavo]

So I began studying Bach's Sinfonia in C major. It has been amazing both for the beauty of it and the huge amount of thinking it takes to find your way around some passages (and this occurs almost in every bar!) By the way, for anyone studying the piece, Gieseking and Leimer's book "Piano Technique" dedicates a couple of insightful pages to it (and to the first invention also).

Anyway, in the fifth bar, Gieseking points out the difficulty of creating a legato from E to D in the middle voice, since it is to be played (according to him and, apparently, to Czerny's edition, which is the image I attached) with a "gliding" thumb (that's to say, both E and D are to be played with the thumb).

So I'd like some advice on the technicalities of this movement. Is the sliding done as in a glissando (using the nail)? I've found that it can also be done by sort of pushing the D with the thumb's first joint as the tip of it is still pressing the E and then kind of stretching the thumb to end pushing with its tip the D. I'm not sure if I'm explaining myself well  The main problem I've had with the "glissando" (and obvious) approach is that it's really hard to control the loudness of the D in that way. So that's why I'm looking for an alternative approach (IF there is one).

Cheers!

[brogers70]

I had a teacher who was very keen on finger swapping, and I'm sure he would have suggested the following. In the first beat you have 5-1 playing the D-G, then the middle voice does F-2, E-1. Then play the C in the upper voice with 4. Now you do a quick 4-1/5-2 swap, so you are holding the C with 5 and the E in the middle voice with 2. Then you can play the D with 1 without sliding. I just tried it out and it seems fine (but then my teacher really drilled me on those sort of swaps, as an exercise I used to do scales in sixths 4-1/5-2, doing the finger swap on every note.). Give it a try and see if you like it.

[gustaaavo]

I had a teacher who was very keen on finger swapping, and I'm sure he would have suggested the following. In the first beat you have 5-1 playing the D-G, then the middle voice does F-2, E-1. Then play the C in the upper voice with 4. Now you do a quick 4-1/5-2 swap, so you are holding the C with 5 and the E in the middle voice with 2. Then you can play the D with 1 without sliding. I just tried it out and it seems fine (but then my teacher really drilled me on those sort of swaps, as an exercise I used to do scales in sixths 4-1/5-2, doing the finger swap on every note.). Give it a try and see if you like it.

Thanks Brogers!! At first, I thought that your suggestion sounded really difficult (like, a lot more than learning that thumb gliding). But I went to the piano and gave it a go and it is really doable.  I even did a little bit of that excercise you mention to internalize the movement (I would've never thought of swapping fingers for two simultaneous notes!) Anyway, yours seems to be the best solution for this passage, no nonsense.

Anyway, I still have some curiosity about that thumb gliding. Leimer writes enphatically about it in the book I mentioned, but I can find nothing about it on the internet. I'll ask my teacher about it, of course, but he's out of town so I have to wait something like 10 days. Does anyone here use this technique or have any thoughts about it?