Post Practice Improvement (PPI)
There is only a certain amount of improvement you can expect during practice at one sitting, because there are two ways in which you improve. The first one is the obvious improvement that comes from learning the notes and motions, resulting in immediate improvement. This occurs for passages for which you already have the technique to play. The second one is called post practice improvement (PPI) that results from physiological changes as you acquire new technique. This is a very slow process of change that occurs mostly after you have stopped practicing because it requires the growth of nerve and muscle cells.
Therefore, as you practice, try to gauge your progress so that you can quit and go to something else as soon as a point of diminishing returns is reached, usually in less than 10 minutes. Like magic, your technique will keep improving by itself for at least several days after a good practice. Therefore, if you had done everything right, then, when you sit at the piano the next day, you should discover that you can now play better. If this happens for just one day, the effect is not that big. However, the cumulative effect of this occurring over weeks, months, or years can be huge.
It is usually more profitable to practice several things at one sitting and let them all improve simultaneously (while you are not practicing!), than working too hard on one thing. Over-practicing can actually hurt your technique if it leads to stress and bad habits. You do have to practice a certain minimum amount, perhaps a hundred repetitions, for this automatic improvement to take effect. But because we are talking about a few bars played at speed, practicing dozens or hundreds of times should take only about 10 minutes or less.
Therefore, don't fret if you practice hard but don't see much immediate improvement. This might be normal for that particular passage. If, after extensive analysis and you can't find anything wrong with what you are doing, it is time to stop and let the PPI take over.
There are many types of PPI depending on what is holding you back. One of the ways in which these different types manifest themselves is in the length of time over which they are effective, which varies from one day to many months. The shortest times may be associated with conditioning, such as the use of motions or muscles you had not used before, or memory issues. Intermediate times of several weeks may be associated with new nerve connections, such as HT play. Longer times may be associated with actual growth of brain/nerve/muscle cells, and conversion of slow to fast muscle cell types.
If you had developed certain bad habits, you may have to stop playing that piece for months until you lose whatever bad habit you had developed, which is another form of PPI. In most cases of bad habits, it is not possible to identify the culprit, so that the best thing to do is to not play the piece and to learn new pieces instead because learning new pieces is one way to erase old habits.
You must do everything right to maximize PPI. Many students do not know the rules and can actually negate the PPI with the result that, when they play it the next day, it comes out worse. Most of these mistakes originate from incorrect use of fast and slow practice; therefore, we will discuss the rules for choosing the right practice speeds in more detail in the following sections. Any stress or unnecessary motion during practice will also undergo post-practice enhancement. The most common mistake students make to negate PPI is to play fast just before quitting practice. The last thing you do before quitting should be the most correct and best example of what you want to achieve. Your last run-through seems to have an inordinately strong PPI effect. The methods of this book are ideal for PPI, mainly because they emphasize practicing only those segments that you cannot play. If you play HT slowly and ramp up the speed for a large section of any piece of music, PPI is not only insufficiently conditioned, but also becomes totally confused because you mix a large proportion of easy material with the small amount of difficult ones. In addition, the speed, and probably the motions are also incorrect.
PPI is nothing new; let's look at three examples: the body builder, the marathoner, and golfer. While lifting weights, the body builder's muscles don't grow; he will in fact lose weight. But during the following weeks, the body will react to the stimulus and add muscle. Almost all of the muscle growth occurs after the exercise. Thus the body builder does not measure how much muscle he gained or how much more weight he can lift at the end of the exercise, but instead concentrates on whether the exercise produces the appropriate conditioning. The difference here is that for piano, we are developing coordination and speed instead of strength and endurance. Thus, whereas the bodybuilder wants to grow the slow muscles, the pianist wants to convert the slow muscles into fast ones. Another example is the marathon runner. If you had never run a mile in your life, and tried it for the first time, you might be able to jog for a quarter mile before you need to slow down for a rest. After some rest, if you tried to run, you will again tire out in a quarter mile or less. Thus the first run resulted in no discernible improvement. However, the next day, you may be able to run a third of a mile before tiring -- you have just experienced PPI. If you run incorrectly, you can create problems; for example, you might develop a bad habit of stubbing your toe if you push yourself too far and keep on running when you are too tired. This is the analogy to acquiring bad habits if you practice the piano with stress. Golf presents another excellent example. Golfers are familiar with the phenomenon in which they can hit the ball well one day, but terribly the next because they picked up a bad habit that they often cannot diagnose. Hitting the driver every day tends to ruin your swing, whereas practicing with the #9 can restore it. The analogy in piano is that playing fast, full tilt, tends to ruin the PPI whereas practicing short sections HS tends to improve it. Clearly, the conditioning procedure must be well understood in order to assure the desired PPI.
Most PPI occurs during sleep. The sleep must be the normal, over-night type with all of its major components, especially REM sleep. This is because most cell growth and repair occur during sleep. It is why babies and young children need so much sleep -- because they are growing rapidly. You will not get good PPI if you did not sleep well that night. The best routine for using PPI is to practice in the evening for conditioning and then reviewing it the next morning.