When I play any sheet music by memory, if I realize (by ear) that I play one wrong note, I always stop/get stuck and cannot continue playing. This is very bad in case I need to perform.
So how to play a wrong note without stopping? Or I should just keep trying to play a sheet perfectly before performing, and refuse to play a sheet that I'm not sure I can play perfectly?
I have been learning piano for a few months now.
The most common cause I've encountered for this kind or problem is practicing primarily from the beginning a piece.
Beginners tend to learn music by developing muscle memory that is associated with the sounds of that music. When the sound or the muscle memory is interrupted, the performer becomes lost. There are no other memory sources (e.g., knowing each individual note, the harmonies, being able to play by ear) to back things up. Thus, the music must be restarted from the very beginning.
It's similar to traveling to a familiar location when one always starts and end the trip from the same places. If there's a different starting place, or a wrong turn, or the familiar trip is somehow interrupted, one becomes lost unless there's good enough knowledge of what went wrong, the surrounding area, or some other cue to help get back on track.
The starting point to fixing this kind of problem is to practice starting from different places in the music — first with the sheet to help, then from memory.
Suppose a mistake occurs at measure X. First, practice measure X by itself. Then start one measure before. Then start at the beginning of the phrase. Try starting in the middle of a random spot near X. This will force your mind, ear, and fingers to learn to music from many different perspectives, and when done sufficiently, will carry you through even when mistakes are made.
In addition to the "mechanical" practice described above, there is also the musical/emotional meaning of the piece. Mistakes — and the difficultly in continuing past them — often stem from an incomplete connection with the feeling of the music.
When a mistake occurs, it is crucial, beyond just drilling the notes, to ask what those notes mean. What is happening in the phrase of which they're a part? Is it climactic? Tragic? Exciting? Is there a specific image or story involved? And what role does this note, chord, or passage play within that meaning? Is it the high point? A rest point? A passing-through point?
These kinds of emotional "through-lines" in music can carry us along even when "surface detail" (like notes, rhythms, dynamics, etc.) eludes us.
Consider that when you speak, you can forget a word, use the wrong word, stumble, forget what you were saying, and the person you're talking to still gets your meaning, because they have a feel for what you were saying. Music is the same. Capture the feel, and know "the story" of the music, and that will sustain you through missed notes.
This answer is just based on my personal experience. I never had this problem, and I'm mostly a guitarist who plays rock music. When I first started I often played along with recordings. If I missed a note, the music went on without me and I had to catch up. So perhaps you should play along with recordings also. Having to figure out where you were when you mess up is an important skill if you're ever going to play with other musicians.
I've said that, if possible, you should play with people and in front of people. "With people" because you have a set of things you think are important, but when you play with others, your failing are clear and they will let you know. Most likely, it's time, intonation, dynamics, and listening to others, but it could be other things.
In your case, it's the mindset of playing in front of others that's important. Basically, "the show most go on". The song can't end and start over just because you threw clams. Good musicians in the practice room will give you room to get it right, but on the stage, you just need to acknowledge it to yourself, get over it, and move on.
There's a line that, when you play the wrong note, you should play it again, hard, so it sounds like you meant it. That might be a mindset to get into. If it's the same note at the same time, though, you should take that part slowly to get it under your fingers. Practice doesn't make perfect, it makes permanent, so if you keep practicing the wrong note, it'll always be there.
You could simply be in the habit of stopping to correct mistakes. I advise my students that you practice in two ways (well, hopefully hundreds of ways, but at least these two): When first learning a piece you should never let a mistake go past without correcting it, and when preparing for a performance you should spend at least some time playing straight through without stopping for any reason. Perhaps you just need to spend more time in the second way of practicing. And it can be hard to "remember" not to stop, so many of the strategies already suggested here can be helpful: Book small, informal performances before "the big one": Play for friends, in a coffeeshop, on the sidewalk, for a video recording, etc. Play along with recordings.
You mention that you stop "usually in a hard part/measure that I often forget after (long) time.” This suggests two solutions:
There are a few other reasons that one might stop when making a mistake:
'Well, don't do that then' :-)
OK, that doesn't help much. Yes, a wrong note can be an obstacle. Particularly if you played the clunker because your hand was in the wrong position. And because a lot of our music reading isn't about individual notes, but about patterns. G,A,B is 'G then one up then one up again'.
I can only offer you the standard advice. Practice slowly enough to NOT play wrong notes. Four wrong attempts followed by one correct one isn't success, it's four practices of the wrong one! Play it right, then play it right 10 more times. 'An amateur practices until he gets it right, a professional practices until he couldn't get it wrong.'
Just don't stop but keep going as if it didn't happen and don't worry about it, things will improve with time. A lot of musicians "train" themselves to stop and consequently don't play nice with others. Never ever stop. However, this is a good time to work on your ear training. Ear training should not be seen as a separate skill but something to amalgamate or crosspollinate with your existing skills.
Most of us learn scales by their letter names, learn them by their numeric names. Instead of seeing (and hearing) CDEFGABC, learn them as 12345678. Thus, MARY HAD A LITTLE LAMB, regardless of the key, is:
3212333 222 355 3212333322321.
Start on the third tone of any scale and play those numbers and poof, you can sight transpose. Don't be satisfied with merely matching dots to a key. Learn the vocabulary. So if you are not sure what that fifth tone is when you are playing, if you know what a fifth sounds like, you will never have to guess, your brain will just know. You will hear it in your head and . . . just know.
It is no different from spelling a word you don't know. You use your existing KNOWLEDGE of spelling rules and sounding out the syllables (spelling by ear/playing by ear). There is nothing hocus pocus about it, it is employing your brain and not guessing nor learning music merely by rote.
Secondarily, this is the beginning of honing your improvisational skills. Should you hit a wrong note, you'll be able to use it as a passing tone, neighbor tone or tension tone to make your piece more interesting. Don't be fooled into thinking a "classical" piece is a museum piece. I'm sure Bach or Chopin never played one of their own works the same way twice. They were improvisors who wrote out their music for students or profit. We don't have to be slaves to their notation.
So build your confidence, ear and brain by playing like nothing happened BUT MAKE NOTE OF IT and go back later to fix what your brain doesn't know yet. Just like spelling, mistakes are lack of knowledge, not talent. Just listen to all the "mistakes" this guy makes:
It can be a bit jarring to keep playing when you know you've messed up. Feels like it messes with the whole rhythm.
Practice practice practice is the best thing to do. If you go through a piece and make a mistake, push it a couple more bars before stopping.
The main thing that got me through this issue when performing is knowing that nobody knows you've messed up. To you it seems like the end of the world but in reality if you keep playing nobody will know any different.
I think an important thing to do is prioritize rhythmic integrity over pitch, or at least treat them as equal. From a listener's perspective I think a wrong pitch is fleeting, but stopping completely, going back even, is a complete collapse of the musical experience.
The way I look at it is this. The first "wrong note" or "mistake" that people recognize is a wrong pitch. For example, you hit an A instead of a B. When that happens, you stop, get frustrated, then start over probably from the exact point of the mistake.
What that does is take a mistake in pitch, and compounds it into a mistake in rhythm! It also trashes the sense that music is a series of coherent phrases, because you might start up again in the middle of a phrase. And let's make one thing very clear: music is a temporal art, no amount of going back and replaying something, in a performance, will "fix" anything. Once it's broken, it's broken... so keep playing.
...refuse to play a sheet that I'm not sure I can play perfectly?
That seems like circular thinking. How would you be able to play something perfectly without practicing it where surely you will make mistakes?
There is a Catch 22 here. You don't want to make mistakes while practicing, but part of the issue is how to avoid stopping when a mistake happens. You want to somehow create "opportunities for mistakes" so you can practice a not stopping reaction.
Potentially there are two different issue at hand. One is how to practice to overcome difficult passages where you make mistakes. The other is how to break the reflex of stopping when a mistake is made. Those are two different issues.
I think there are two main things to work on:
In both cases I think a good principle is taking some extra time, a "breather" to regain your composure, at a musical cadence point, is OK. That at least works within the natural start/stop structure of the music itself.
Overall, avoid stopping by focusing on the beat and rhythm.
That problem was for me and I was looking for answers in a lot of places. What helped me: I played something that I really know every character and could start from anywhere in the piece (it's very important!) and played in front of a lot of people. You don't need a lot of people in front of your family before - call everyone at the piano a deep breath and think like this is the last time you play the piano How would you play then?
One of the things you should do so as not to get to such a situation is to learn each hand individually slowly until you can do it really quickly and immediately after it very slowly - until you really know each note it is very important. Another thing I do when I train is learning to start from the middle of the piece from a complicated place. It helps to get to know the characters better.
