There are moments in the life of an instrumentalist when nothing works, when you hit a wall, when you can't find the solution to progress and achieve a satisfactory result.
Sometimes, motivation even suffers as a result.
So how should we proceed, and what working method should we adopt?
There is a method that does not immediately spring to mind, but which is extremely effective: working very slowly and sufficiently to give the brain time to learn, without stressing it, for example by demanding impossible feats such as reproducing a page or an improvisation grid without even taking the time to study it thoroughly, from all angles and in all its aspects.
The more resistance there is, the slower you need to start, and for a very long time!

After that, the brain will reproduce any work at the desired speed, with a smile and in a relaxed manner.
And then slowness is the key to pleasure. So let's hurry slowly.
Methodology and perceived effects:

I set my metronome to forty-five and work on a written score or improvisation based on a grid. Then I start again, increasing the metronome by five points, to fifty bpm (beats per minute). It's difficult to feel the acceleration at this tempo, and yet...
I repeat the process several times. Meanwhile, my heart rate has slowed down, as has the frequency of my alpha waves. My concentration is stable, and I feel calmer.
Time has passed, but I no longer attach the same importance to it; it has become pure illusion, its hold on me fading. The agonizing voice whispering "you're wasting your time" has finally fallen silent. Several more hours have passed, but I feel no fatigue and my muscles are increasingly relaxed; I am constantly monitoring this. The positioning of my hands, wrists, elbows, and fingers has become natural and optimized, making them as ready as possible at the moment of truth, where they need to be in order to play effortlessly. I have settled into a steady, repetitive rhythm. My mind is sharp and clear, alert and awake. A peaceful horizon full of possibilities opens up before me.
Contrary to my initial feeling, I am not wasting my time. I am investing time at the beginning in order to reap the rewards later, with the added bonus of acquiring a solid technical and musical foundation.
Because movements and fingering are gradually recorded, resulting in relaxation and confidence that gradually resolves all the tensions caused by uncertainty, imbalance, and the urgency to find even a shaky solution to play the notes without knowing exactly where they are located or which fingering to use. The same applies to nuances, dynamics, and phrasing.
Economy of movement
My movements are reduced to the bare minimum, my hands hardly move at all, no extraneous gestures disturb the minimum required to play what I improvise or the written music I interpret.

I remember my aikido teacher during randoris (sparring sessions at the end of class) when several of us would attack him in quick succession. he hardly moved, was very grounded (the "Ki"), but no one could touch him because his defense was precise to the millimeter, a simple, well-placed arm movement was enough. We were thrown left and right with the same energy we used for the attack, energy that turned against us, the basic principle of this sublime martial art.
Absolute economy of muscular effort is fundamental in any sporting or instrumental activity.
Watch a beginner on skis, roller skates, or ice skates, and you feel sorry for them because they make so many counterproductive and dangerous movements!

How can you hope to program the right movements without playing very slowly at first?
Even a slow medium tempo is still too fast to "program" everything necessary for the perfect performance of a piece.
How much time and motivation will then be needed to unlearn the bad habits acquired in the rush of a poor start?
Imagination in the service of learning
During this type of practice, the body evolves slowly. I imagine and reproduce on the piano a film showing a cheetah running in slow motion. I can then break down and reproduce the overextension of its limbs, stretched to the extreme, which then cross over each other as much as possible, over and over again. I don't play slowly, I simulate fast playing in slow motion, which is very different.
But what is important is that the brain is working at full capacity. A huge number of parameters can be taken into account during this slow work. I can concentrate on the speed at which I press the keys to control the nuances and touch, fix the fingering, program the movements of the elbows and wrists, the lateral spacing of the fingers (the fingerprints) to play the chords, and making sure I hit the middle of the key with each stroke.
In this regard, I imagine, for example, during this meditation in action, that I am shooting a bow and arrow. It doesn't matter whether I look at the target, in this case the center of the target, or not. I visualize it in my mind. When I release the arrow, I know it will reach the target because that is when I had the internal vision of it.

The same applies to rhythmic placement. Here too, the concept of the "middle" of the beat, or slightly "ahead" or slightly "behind" the beat, comes into play. The metronome serves as a benchmark for testing different alternative rhythmic placement solutions, but always in a controlled manner.
The metronome also forces you to respect the various stages of speed increase without giving in to the temptation to play too early, too fast, and lose control, to be "played" by your fingers.
What is remarkable is that all of this constitutes extremely precise learning because, at the same time, the body and mind merge and learn by memorizing everything, as if we had become a tape recorder. All of this will be reproduced at speed; it's hard to believe at first. It's like taking a step back to jump further.
Anticipation

During the final execution, anticipation will be key to being able to "see what's coming" and resolve any problems caused by a few milliseconds of distraction, hesitation, or a mini memory lapse. It's a bit like the buffer memory of an online video player. The loading bar is ahead of the playback bar. From time to time, the gap between the two narrows when loading stops momentarily while playback continues at a steady speed. But when the playback bar catches up with the download bar, which has stopped completely, there is no more space for the buffer, and video playback stops abruptly.
When playing "in tempo," whether improvised or not, a lack of anticipation puts us in constant "danger" and creates debilitating tension. It is impossible to correct anything in advance, so we proceed by trial and error, nose to the grindstone, without the necessary perspective to solve problems that we can nevertheless see coming.
This anticipation can range from a few milliseconds to a few measures, or even more. There may even be several different anticipation patterns superimposed simultaneously in order to also predict the upcoming form, nuance patterns, color changes, or any event that will make the performance interesting.
Anticipation is also the basis of the art of deciphering...and of management in general.
Anticipation can be practiced, learned, and programmed. We train our brains to anticipate at the same time as we learn notes, chords, and fingerings. Anticipation must become a reflex, just like everything else. It is our confidence. Anticipation must be a fundamental task present in any learning process, right from the start.
However, in slowness, learning to anticipate requires at the same time accelerating the process of thought and mentalization.
Multiple overlapping speeds
As a result, we find ourselves managing several different and simultaneous speed plans: those relating to the slow execution of muscles, fingers, elbows, wrists, and hands on the one hand, those relating to rapid thinking in action on the other, and those relating to all the elements we want to include in the "anticipation" file on the other.
These may be short- or medium-term achievements and require more or less rapid processing by the mind, or even ultra-rapid processing in the case of high virtuosity or superimposed counterpoint during improvisation.
A short metaphysical journey

This superimposition of multiple speeds is a phenomenon that can be found in many other areas of life in almost identical form. We probably evolve in a slow sine wave, in which other sine waves with multiple frequencies are embedded. Take, for example, the movements of the Earth as it rotates around the sun. It oscillates in all directions, spins on its axis, and revolves around the sun, all at different and simultaneous frequencies.
Or visualize the rhythms of our lives and their different frequencies, imagine their cycles in terms of seconds, minutes, hours, days, weeks, months, years, decades, centuries, life, etc. Now superimpose all this on a moment "T." The concept of horizontal time no longer exists. In this meditation, time is conceived vertically. Everything exists here and now, and, if we take this concept to its logical conclusion, the moment is perfect.
And, why not, hope can finally be reborn! Since "before," nothing can be done, and "after," we still don't know anything.

In that case, why rush? Why not fully appreciate and make this perfect moment last as long as possible?
In cognitive psychology, we know that behind the message "hurry up" lies another message: "don't enjoy yourself"!
Under these circumstances, it's no wonder we lose motivation.
A little experiment to try:

Try walking slowly for once, very slowly down the street, wandering aimlessly and observing everything around you. Also observe what happens inside you once the strange feeling you had at the beginning has passed.
The world will smile at you in an unusual way, things will catch your attention, you will enter into a mode of observation rather than action.
In this way, you make yourself available, and that is precisely the essential condition for achieving concentration.
Concentration is not a withdrawal into oneself, but rather an openness and peaceful receptiveness to the world around us.

So let your fingers carry out the commands of your brain, which you have given time to learn, while you meditate in a contemplative, receptive, imaginative state, free from fears and tensions, and open to the pleasure felt thanks to this slowness, which is in reality quite relative.
Under these conditions, practicing will be a pleasure, and returning will be a necessity!
My own experience with Bach

To work on these three Bach preludes and fugues, it took me about two hours per tempo section. Starting at 45 bpm and increasing by 5 bpm each time I repeated the whole piece, I managed to fit in four passages from the complete work in a day, from 45 to 65 eighth notes per minute, which is about eight hours of practice without getting tired!
I was looking for perfection, absolute equality between attacks, and the possibility of subsequently concentrating solely on interpretation, without thinking at all about the notes in the text. The latter had to be entirely "automated."

The result after about ten days was phenomenal! I started playing the three preludes and fugues at high speed. Everything flowed naturally, evenly, without a single wrong note, with complete mastery of all the parameters. I could see my fingers playing at full speed, but this time my mind was completely free and moving slowly, calmly, and it made me burst out laughing while playing...the last fugue of The Well-Tempered Clavier with its formidable trills!
From that point on, I was able to devote myself entirely to interpreting, and I really enjoyed it!
Does all this sound unbelievable? Then try this horse remedy for ten days on a few difficult pages that you're struggling with, or on a particularly daunting improvisation grid, or any other sporting, artistic, or other activity.
After all, what are ten days in the grand scheme of a lifetime of hard work?
Instructions for use, dosage:
• Set the metronome to forty-five on the half beats or on the weak beats (the second eighth notes or beats two and four) or on all beats, as desired.

• Play these pages or improvise on this grid (or on four or eight measures in a loop only, as you choose), focusing on perfecting the notes, sound, and timing, placement, relaxation, fluidity, etc. Work on anticipation! Gently enter this world of extreme slowness, this unusual meditation.
• Immediately identify passages that do not work and repeat them several times at this very slow tempo until they feel fluid and can be read in their entirety without any mistakes at this tempo.
• Once everything is played flawlessly at this tempo, confirm and increase the speed by five points on the metronome.
• Repeat this process until you reach a slow medium tempo (perhaps around seventy bpm?). Above all, do not go beyond this.
• Repeat the same process, starting again at 45 bpm the next day and the day after that, every day for a week to ten days, without ever playing at a fast tempo so as not to destroy what is being created by "recording" flaws without our knowledge.
· After ten days, following a break of a day or two, play for the first time at a fast or even ultra-fast tempo, and the result will be astonishing!