A student of mine told me a story about her childhood teacher. The student was playing a piece, and was struggling to manage it, which resulted in, naturally, a fair number of wrong notes. The teacher stopped her, closed the music, and said, indignantly, "This is a waste of my time. Come back when you can play it with fewer wrong notes." Incredible, isn't it? If only the child had said, "Isn't that what you are supposed to be helping me with??" And we've all heard the stories of children who were rapped on the hand every time they played a wrong note. Note errors were, and still are, for many people, sadly, viewed as a personal failing.
The typical approach to wrong notes is simply to "correct" them each time one is played, that is, to stop, play the intended note, and then move on. You probably will have noticed that if you play an incorrect note, it probably happens most of the time, even every time, you play that passage. Stopping to play the "correct" note, in fact, doesn't actually correct the problem. It just reinforces the habit of playing the incorrect note, quickly followed by the correct one. You may have the illusion that you are correcting the problem, but in fact you are making it worse. When you correct a note, you have now altered the rhythm, which is equally a problem, in fact more so than a wrong note or two. I find with many of my students that if they stop to try to fix a note, it invariable leads to another problem right afterwards, and another, and sometimes the whole passage starts to unravel.
When we perform in public, it is universally understood that it is verboten to stop to correct, yet somehow people cling to the belief that they can stop and correct in their daily practice, but when they get on stage they will be able to continue without stopping should a mishap occur. Obviously this isn't the case.
There are many reasons for playing wrong notes. We could have mis-read the note initially and learned it incorrectly, possibly without even realizing it. If so, it may or not be easy to correct, because now we have heard it incorrectly so many times. We could have incorrect or insufficient technique to find and play the note(s) accurately. We could have a weak or incorrect auditory image of how the music is supposed to sound. The auditory image, knowing with absolute inner certainty, how the music should sound, is the single most important factor, in my belief. Without it, your technique, however good, will still not lead you to the correct notes with any real reliability.
How do we strengthen the auditory image? The simplest answer is by REALLY listening. However, when we learn a piece we are often too distracted and even overwhelmed by the number of notes and all the various other aspects, and we are not in fact really hearing the music. That is why I recommend outlining (see previous post) so that we can have fewer notes to manage and have more "space" for listening.
However, the absolute BEST tool for getting the music "into your ear," as I call it, is transposing. If you can transpose a passage, or even better still, the entire piece, you will find out if you really hear the piece. If you can't do this, you just keep at the transposing until it becomes easy. When you transpose to a new key, you are in essence hearing the relationship of all tones to each other. I transpose all my pieces to all other eleven keys, many times over. At first you will need to go slowly, and where your ear fails you, you will use calculation (looking at the music and figuring out the interval distance). Gradually you will do it more and more by ear. For pieces I have studied in depth, I can play the entire piece (including full sonatas of Beethoven, for example) in every key, by memory, slower than the piece is intended, perhaps, but still at a reasonable tempo. Most people find this pretty incredible when I tell them this, but it is absolutely true. In the 35 years I have been doing this, it has transformed my playing in areas such as accuracy and memory. It vastly reduces the pure number of hours it takes to learn a piece. I always find when I am having difficulty with the technical aspect of a piece, strengthening the auditory image of that passage through transposing either helps with the technical accuracy, or often even solves the problem completely. It gives me greater confidence in performing, knowing that I know the piece so well I can overcome any small mishap.
If you are consistently missing a note or a number of notes, your hand is simply not in the right place at the right time to play the correct one. Here, with the help of a perceptive teacher, you need to analyze what you are doing that causes your hand (fingers, arm, even your torso) to be in the wrong place, so to speak. If the teacher points out the incorrect notes but does nothing to help you achieve playing the correct ones, you have the wrong teacher! There can be so many things that can cause your physical mechanism (your body) to be unable to play the correct notes with reliability -- far too many to address here. But when the ear has a rock-solid auditory image and the body is trained to respond to the ear, you can't go wrong.
Lastly, a major cause of wrong notes is the fear of wrong notes! When we are fearful, or demand unreasonable perfection of ourselves, we tighten up physically, which hampers the ability of the body to move smoothly and respond to the music. And the constant fear of or anxiety about wrong notes certainly spoils the enjoyment of playing.
So what to do? When you play a piece of music, PLAY WITHOUT STOPPING! You will not learn wrong notes this way, as people mistakenly believe. Instead, you will keep the rhythm intact (which is extremely important), and you will keep the integrity of the composition rather than chopping it up. Play with all the beauty, expression and creativity you are capable of! Afterwards, you must go back through the places you had errors and try to analyze why you had them. First and foremost, strengthen your auditory image of that passage through transposing. Try transposing with your eyes closed! Play the passage in the original key with eyes closed to see how well your body alone leads you to the correct notes. Investigate whether your hand is twisted or otherwise out of position to play the intended notes. Find a teacher who can really help you with these areas. (In future posts I will try to address more aspects of technique.)
My teacher, Joseph Prostakoff, often said: "If you want to play beautifully, you must learn to love the wrong notes as much as you love the right ones." This is the most profound statement I ever heard about learning to play the piano. I certainly endeavor to play with note-accuracy. I work at it diligently using every tool I have. But I don't let a few wrong notes spoil my experience or joy of playing. I don't play with the fear of having wrong notes. When you experience the freedom of playing without this fear, you will never go back to the old ways.