The mechanics of chaos vs the mechanics of predictability- what quality of movement offers the best tonal control over ppppp, FFFFF and every possible shade in between?

Nb. This post is all about the consistent factors behind control over sound. After outlining some very basic issues about what defines control/the lack of, I'm also going to talk a little of the great artist Shura Cherkassky's methods- and illustrate quite how neatly his approach to the keyboard corresponds with what mechanics suggests to be necessary for close control of sound. Whether we're talking about getting the softest sounds possible or the fullest ones, the essential basis for control is scarcely different. Likewise, staccato and legato have a lot more in common than most people realise. Much the same basic issue dictates whether the precise sound produced is primarily defined by artistic choices, or by mere chance factors that pollute the result. This was originally the end of my previous post on the concept of "positive movement" vs "negative movement". However, as that post was rather long (and as the issue of tonal control is quite so important) I decided to expand that segment into a separate standalone post. Please start by reading the definitions in that post- so you can appreciate what I am actually referring to via these original terms. However, in order to understand why these issues are at the very core of what defines the possibility of controlling your sound, it's not necessary to read the full post right now, but only the definitions. Also, please note that additional illustrative videos will shortly be added to each of these posts.

Why is "negative movement" (a squashing of the distance between knuckle and fingertip during the key depression, as per the diagrams) the single biggest enemy to a pianists control over sound?

Well it's very simple to prove. Basically if two bodies are in contact and one is accelerating the other from behind, as soon as the one at the back starts to slow down a little, the other will start to escape on existing steam. At this point it is coasting and you have given up your means to manipulate it any further. Even if you should catch up again, merely by bobbling in and out of contact, you have already lost the simplicity and directness associated with staying in touch continuously. When a hand collapses as shown, during key depression, it can be said with objective certainty that the knuckle is travelling faster than the fingertip- (which is why the distance between them is becoming progressively smaller). This suggests (with near certainty) that the fingertip is losing available speed while moving the key, rather than accelerating continuously through- which renders it impossible for that fingertip to be passing on speed both smoothly and continuously, in the most predictable fashion. The transfer of energy is necessarily "chaotic"- which means that a very small change in one variable can result in a very significant change to the final result in sound.

If that's not making sense yet, there's a more specific situation that's very easy to imagine, that should readily demonstrate both the truth and significance of this broader principle. Imagine standing still behind a line and pushing a supermarket trolley into motion (without being allowed to take any steps forward, beyond the line). Let's say there's a target a certain number of metres away and you hope to roll it into stopping there, or at least come as close as possible. It's not a miniscule distance but it's not especially far either- say 5m. Is it easier to give a short sharp jab or is it easier to connect clearly with the trolley and then gradually push through until you can stay with it no further? Well, the greater the distance of travel during which you can stay in steady contact, the more margin of error you have (I won't bore you by detailing the proof through physics or associated graphs, but any physicist worth their salt will affirm to you that this is an absolute objective truth, with reference to "impulse"). So, for control, you should push continuously over a longer duration, rather than apply an identical level energy through a brief prod. Incidentally, for direct equivalence to the concept of negative movement within a finger, imagine if the distance between your hands and shoulders were to become squashed, rather than grow out through the push. Think quite how hopeless this would make your control of the trolley!!!

Another example I used before is golf- where all good golfers aim slowly but surely through the ball for short putts- and never hold back or start to slow the club as it reaches the ball! The simple reason is that slowing down during the movement, rather than accelerating, means there is collossal margin for error. A tiny difference in timing means a huge difference in the result, as per chaos theory. There is more inherent predictability when a small but increasing level of force is applied steadily over a longer distance of contact. To put that more simply in layman's terms- you need to putt by aiming steadily THROUGH the ball, rather than move sharply but with intent to stop the club upon contact. Nobody could succeed with a technique that is objectively unfit for the purpose of achieving a high level of accuracy. This isn't a matter of subjective preference- as evidenced by the fact that a golfer who jerks at his putts by slowing down the club is literally unheard of at professional levels. If you care to do well, you need to use a technique that gives you decent odds of getting as close as possible to intensity of kinetic energy that you had actually aimed for.

Going back to the trolley, if we only wanted to move it by a mere 2cm then a shorter prod might be more accurate- but only for the reason that a longer contact would necessarily apply too much energy and would thus mean overshooting the target. However, remember that even the softest pianissimo playing must swing the hammer all the way to the strings. No note that sounds involves the barest minimum. Silent key depressions are the bare minimum- and those are really not something we want when we're supposed to be producing tone! By analogy we're not in a situation where prolonging contact will automatically mean overdoing it. Moving the key too fast is the only way to overshoot your intended volume, so there is no associated benefit to trying to keep the contact short (at least, not when striving for a very soft tone- I wouldn't rule out sharper attacks for specific tonal effects at higher intensities). Making a lasting contact adds scope for control of tone, but does not in any way mean sacrificing the possibility of softness. The classic mistake is to become less positive when trying to play soft. However, moving steadily but with a positive quality is the very thing that makes it possible to play truly quietly- without either risking missed notes, or compromising the level of softness for the sake of avoiding them. 

At the piano, try either pecking at a note and then pulling the finger right back (rather than aiming through a longer contact) or allowing a finger to buckle into negative movement.  This will tend to allow the hammer to escape from your influence sooner, just the same as if you prod abruptly at a trolley. When you stay in contact over a longer distance (by starting gradually and accelerating right through to release) you have more scope to judge exactly how much energy and therefore tone you will pass on. It's important to note that the piano has a point called "escapement", after which the hammer always gets released from your direct manipulation. However, while you can't change anything after that point, what you could very well do is lose consistent contact with the hammer before that point is reached- should your fingertip start slowing down rather than accelerating. It's very easy to overlook this, but it is quite possible to lose influence prematurely.

This is why you should NEVER think of making the fingers more passive or floppy for soft playing! Fingers with give mean you cannot accurately predict either how long you are manipulating the hammer for or precisely how much speed it will receive during that time- before it escapes you. But don't stiffen the fingers either! You can achieve all the "firmness" you need by preventing negative movement in the same way that you always should.  Reliable control of soft tones comes when you bond with a hammer by starting very slowly against the key's resistance but then use "positive movement"- so you are always accelerating the fingertip through subtle resistance until the hammer is set free. The acceleration will be more slight of course, when speaking of soft playing, but you have to stick with it until the hammer is already gone, if you want fine control. This is equally true of any dynamic- which is why the most polished performers move so effortlessly between levels. They're not switching between radically different concepts but doing much the same basic actions, with simply more or less intensity to correspond with the dynamic. In soft sounds, the trick is not to be pulling back with any repression but using a positive and deliberate movement throughout. It's always easier to judge the result if you slowly increase a gentle force, over a longer time, than it is to judge a larger force for an ultra-short duration.  The great pianist Josef Llhevine spoke of the need to ground every key even in soft playing. Although this advice doesn't quite convey all the deeper nuances that I'm looking to reveal here, I have no doubt that it was his way of encouraging this same positive quality of prolonged contact. If you don't ground the keys, it's a very likely indicator that you are repressing and thus failing to maximise contact with the hammer. Once you appreciate the basic concept, looking to finish grounding every key is a very simple way of checking that you're staying suitably positive, without having to retain any more complex thoughts during performance.

This is why so many great pianists are known to have liked practising soft passages loudly, even. What they were achieving is a consistently positive quality of motion, that was not infected by any trace of repression or give in the fingers. Listen to what the great Shura Cherkassky (an artist renowned for the most astonishingly soft yet defined pianissimos) had to say about how he practised, and watch the few seconds of him doing so, that follow.

 http://youtu.be/zgEwSoA9Dvs?t=50s

A pianist who already thinks like a musician simply cannot lose that, by spending some of his time searching for a simple positive quality of movement from each and every finger. He may not have directly analysed the concept that I have labelled "positive movement" but his manner of practise was quite visibly certainly geared towards achieving a simple positivity of motion. When done with sensitivity, this kind of preparation may be rather musically dry, but it trains the reflexes to work consistently in the most effective manner. Such practise isn't where Cherkassky developed his profound musicianship, but it is where he kept up his ability to control the precise sound of every single key. When he put musical intentions in, this is what he could do:

Note just how vigorously and deliberately he GRABS the keys with his fingers, even in the softest accompaniment notes! The secret here is to remember this:

The finest control over soft playing comes when the finger moves every bit as positively as in louder playing, but simply at a far slower speed.

What we see in Cherkassky is a deliberate movement done very slowly- not a short fast movement that is tempered by repression!!! His dry practise may have sounded like a "piano tuner", as he put it, but it trained the deliberate quality that allowed him to reach such extremes without losing control of his sound. At this point, the less specific concept of "positive thinking" is actually closely intertwined with the more specific notion of positive movement. Mental confidence is much more inclined to generate  positive movement than mental uncertainty. With a sense of being even a little mentally tentative or restrained, negative movement is almost certain to be huge a problem. I always like to think of fingers moving gradually but with extreme power (as if they could slowly but effortlessly cut through a brick wall, if need be) for soft playing- so nothing in the mindset implies anything less than a long movement with intent. I may not be on the level of Cherkassky's astonishing pianism, but in recent months I've made a huge amount of progress in terms of how softly I can play without giving up control, by being aware of these defining issues. In the long run, feeling generically mentally positive can start to look after the physical side- provided that you've already ingrained the more specific quality of the physical habits, of course. But if even Cherkassky saw fit to do his practise that way, there's every reason why lesser mortals should give serious consideration to devoting some of their practise time to achieving a similar straightfoward positive quality- rather than kid themselves that they're too artistic to dirty their hands with such mundane practicalities.

Incidentally, the issue of staying in touch with the key's resistance is another reason why I greatly dislike the idea of moving wishing to move a key "fast" for even loud playing. Any golfer, cricketer, tennis player (or other sportsman who uses their body to transmit movement to another object) will not achieve the biggest distance by merely trying to swing as "fast" as they can. To transfer energy effectively, you still have to pace things so the acceleration increases through contact with the resistance- just the same as for quiet playing. If you don't achieve acceleration right there, a reaction force starts to slow you down, so you lose contact too soon to apply serious impulse to your target. Any good sportsman knows this (in instinct, at least, if not necessarily always in analysis) but, sadly, a lot of pianists really don't have either knowledge or "feel" for this. Some misguided methods even encourage things which are likely to obstruct the process of acquiring that feel, if taken at face value. Rather than be slowed down upon connecting with your target, you need to be able to accelerate the fingertip right through the full distance- so the hammer doesn't escape from your manipulation prematurely.

Even in staccato I've recently discovered this to be important. In fact, perhaps especially in staccato- where it's overwhelmingly common for pianists to lose exact control over the intensity, by backing out prematurely. An excellent comparison is the screw shot in snooker or pool. Although your average pub pool player stabs at the ball to achieve backspin, top snooker players will aim low but cue straight through the ball- in line with the same principle of prolonging contact rather than shortening it. Just because you want to allow the damper back to the string, it doesn't mean you should be thinking about trying to back out before you've even finished manipulating the hammer. Finish the job properly with one simple and unpolluted positive intention (the reaction to which should automatically bounce the finger straight back up anyway) and you'll have vastly more control over the tone than when you "peck" at the keys with needless anticipation of pulling back out.

Anyway, back to the very loudest playing. If we return to the trolley example and picture trying to get the biggest distance- would you rather swing a baseball bat at the trolley as fast as possible (and see it bounce straight off a short and unpleasant contact) or use the same technique of connecting to the resistance, before smoothly accelerating your hands through the trolley in a prolonged contact? I know what I'd do. Although I used reference to relative speeds as a basis to prove that negative movements waste energy on impact, I simply don't think of high absolute speeds as being the way to play loud. I think of feeling the key's resistance clearly and then staying in touch with it as far as possible- by continuously accelerating into the escapement (the level at which the hammer necessarily leaves your control, even when accelerating smoothly). I then smoothly continue the same action, so my hand evolves further into a place of openess and comfort. When I'm playing at my best, I know that the process will feeling surprisingly long, slow and effortless during the biggest sounds- not like a short but violent stab. With suitable use of positive movement, there's nothing to relax from- because your movements are taking your hand towards increased freedom from the very outset, rather than headed for the type of compressed impact from which retreat might be desirable. When you have learned the type of action which actively builds upon comfort, through ongoing continuation, even the very loudest FFFFF can be done without fear of impact or stress. In fact, the more positively the hand performs, the safer it actually starts to become.