I'm making good progress on internalizing the rhythm in measures 25-31, so it's time to turn my attention to something else. Research shows that we remember best what we learn at the beginning and end of a work session, so I usually switch tasks at least every 10 minutes. With a brief mental break, I get another primacy and latency effect for each task. Plus I don't get bored, I give my neuronal pathways time to develop the last task, and I reduce the likelihood of overuse injuries.
I would prioritize my remaining tasks as follows:
1) double string crossings in m. 29-30
2) bring the triplets up to speed
3) add the bowing to the triplets in m. 27
4) bring the whole passage up to performance tempo
I have decided that my final performance tempo will be quarter note = 120 bpm.
Some cellists would find the fast triplets to be the most difficult technical aspect of this piece. For me, it's the double string crossings. I find the combination of left and right hand challenges to be very awkward, especially at a fast tempo. So I would choose working on that as my next task. But as before, I would try to sort out the left and right hands separately. As an aside, I find that the Suzuki books often have good preparatory suggestions for the method pieces. I was a little disappointed in the prep etude for string crossings in book 4. It's just more of the same, which I guess means I'm disappointed it doesn't break it down far enough for my needs. Another exercise for the student, so here I go.
Right hand first. I know that the goal of an efficient string crossing is to play on the "inside" of each string, inside being the closest side of one string to the next string played. Double stops can be invaluable for training the amount of right elbow motion needed to achieve this. (This is true whether you are crossing one string or three.)
Step 1: Analyze the double stops I need. I see both measures are identical except for the dynamics. In each case, the first three pairs of notes alternate from the G string to the A, and the last pair is from the C string to the D. For double stops I will play in eighth notes GD DA GD DA GD DA CG GD.
Step 2: Observe my right elbow motion (height) while playing repeated AD double stops. Then when playing repeated DG double stops. (There is a reason that mirror was conveniently in front of me when I took that picture of John in my last post.)
Step 3: More slowly, alternate DG downbow, pause, lift elbow to AD height while pivoting the bow on the D string, AD upbow. Pause, lower elbow to GD height with bow pivot on the D string, GD downbow. Etc. Set the metronome as slow as necessary so that I don't feel rushed. Stay at the slow tempo until my elbow no longer overshoots its mark and I no longer have the tendency to "lift" the bow between string pairs. Then increase the metronome speed in steps to the intermediate target of 72 bpm. Repeat the entire process for the DG and GC pairs.
Step 4: Alternate playing down GD up DA with down CG up GD, first slowly then gradually up to 72 bpm with eighth note ds.
Step 5: Play the ds pattern I need at 72 bpm. Might start more slowly then increase speed if I can't do it right off. GD/DA GD/DA GD/DA CG/GD repeat
Left hand. Before I go on to cross strings without double stop, I'll learn the fingering. String heights change just enough when the strings are stopped that you have to recalculate crossings, anyway. The key to left hand efficiency in fast double stops is to keep a finger down once it is placed until you need to use it again.
Step 6: analyze left arm motion. Play double stop down GD up DB back and forth (1 down on B). Then down BD up DD (3 down on B, 4 down on D together). Then down AD up DC (1 down on A, 2 down on C together). Then down DG up GF# (1 down on D, 3 down on B together). What I see is a slight rise in my left elbow with each subsequent pair, then drop and repeat the same sequential rise for the second measure.
Step 7: Practice playing the pairs of double stops in order, no tempo, with pause in between. Focus on keeping fingers down together for each pair of double stops. My fingers would move something like: 1 down (B), 3 down (B) 4 down (D), 1 up then down (A), 4 up, 2 down (C) 1 up then down (D), 3 down F#. Next measure open G, then 1 up then down (B), 3 up then down (B), then as before. When I can do this and still be relaxed, start at very slow metronome and gradually speed up to 72 bpm. Have I maintained the elbow motion I saw in Step 6? If not, find the tension I have introduced and eliminate it by going back to slower and building up again.
Step 8: Continue at 72 bpm. Alternate playing the pairs of notes as double stops for a measure then clean string crossings for a measure. I should not be able to see a noticeable difference between the arm motions from one measure to another.
A lot of words, but by writing them down I feel like I understand a good approach to the problem. Not only that, but I tried it out before I sat down to write, and can play those measures up to near my target of 120 bpm. A good night's work, I think.