RFox It was I, not JB_PT, that proposed the initial sort-themselves-out-during-sleep idea.
Thank you for your correction. I edited my post accordingly.
RFox Figure out the measure into workable sized chunks that won't tax working memory - we're not trying to memorise the passage overnight, just trying to figure out a solution.
Thank you so much for your help!
Now, first of all, I did not explain my practising process very clearly to begin with, because I did not think this would be part of the discussion. When I said that after ten days I could play the passage of four measures HT at a certain speed, and later gave an example of what could happen between one day and the next day, I did not mean to imply that on day one of practising I started playing the whole passage HT with my metronome.
No.
The first days I spent practising the measures HS, until I could play them fluently and correctly.
Then I started practising HT, two measures at the time. The two measures each start and end quite doably, but the tricky part is in the second half of the first measure and the first half of the second measure.
Now a large part of why this was tricky was counting rather than correct notes. In the first two measures, there was a triplet with two quarter notes and two 8th notes above four quarter notes. The mistakes I made were mostly playing the correct note at the wrong time. In the second two measures, the triplet had a dotted quarter note, a regular quarter note, and three 8th notes above the four quarter notes.
So I introduced the metronome as soon as possible (already when playing HS), and I counted, counted, counted.
Then I found that I too often confused the counting challenge in the first two measures with the counting challenge in the second two measures, and, conveniently, they were adjacent, so I put them together and started to practise them as a whole. However, I also regularly practised tricky part 1 and then tricky part 2, then did something else, then practised the whole passage again.
After all of this, at the end of a practising session I could play these four measures correctly at 55 bpm for an 8th note. I started to wonder if I really wanted to continue with this piece, and I wrote my post.
RFox 1. [...] This may involve holding down all the notes that are played together, relax all the fingers consciously, figure out the next note or note group, figure out (still holding down the current notes) what fingers will play, rehearse them in your head, imagine the voicing and dynamics if you're that prepared, make the change as quickly as practical and hold down all the playing notes.
This is basically how I practise when a passage consists of consecutive triads, apart from imagining the voicing and dynamics, because at this stage I need all my attention for figuring out the next chord.
Oh, and I don't relax my fingers! But that is actually a very good idea, so I'll try to incorporate that.
RFox Don't repeat this more than two or three times at any one time
Now here is where we differ very much. Because I usually repeat this process until I feel something click inside of me. An "Ah now I get it" feeling. Then I take a break from the passage and play something else.
RFox 2. Don't try to speed it up on the same day. If you're adding a second session five or six hours later repeat the first attempt.
So, two or three times only, and then once again two or three times only - leading to a grand total of six times every day. 😲
But you inspire me to experiment with this. Tchaikovsky's In church is on my list of pieces that I sooner or later will play, and RH m33-36 seem to be very suitable for this type of practising. Each day I will record the total time needed for these four chords, both the first time I play through them and the sixth time.
RFox I would drop the passage for a week at this stage and work on another piece. When I get back to it the brain should have made everything run a little smoother and a little easier.
Unless I know a piece very well, this has never been my experience. But now that I am experimenting, I will do as you say. 😇
It will be really exciting! Thank you so much for inspiring me to experiment in this way. 😍