Mistakes are easy to spot. We hear a wrong note, an incorrect accidental or rhythm. We can feel it - it just wasn't right.
But is your mistake simply that - an error - or it is a symptom of a larger problem? And how would you know the difference?
Sometimes a mistake is just a random slip, in the way that sometimes a sneeze is just a random sneeze. But we know that if we start sneezing more frequently, that mya be an indication that we are coming down with a cold, or that our allergies are flaring up.
A random sneeze requires a tissue. A cold or allerguies may call for a trip to the doctor.
A random mistake is easily corrected with an extra moment of attention.
But a mistake that keeps occuring is rarely just a mistake. If you have caught yourself saying, "I did it again," or "I always do that," then you can be sure that you have a problem to address, not mermely a mistake to fix.
The good news is that once you realize you are facing a bigger issue, the steps to correct it are fairly clear. You follow the four "F's."
You suspect there is an underlying problem. Now you need to figure out what it is. Begin by examining the spot where your error occurs. What exactly happens when it goes wrong? What do you do differently when it goes correctly, assuming that sometimes it does?
Perhaps the issue is a technical or coordination problem. This kind of problem is related to your hands or your fingers. Your hands won't work together or your fingers aren't managing the coordination that the piece requires. Maybe speed is the sticking point.
Or the underlying problem may be incomplete or insecure knowledge of that particular place in the music. You just aren't as familiar with that spot as you need to be. You may not know all the notes in the left hand, or all the notes in a chord or arpeggio. If you experience a little jolt of surprise or confusion when you get to that spot in the music, you are dealing with a familiarity problem.
If you suspect the problem is a technical or coordination problem, then you will need to determine the appropriate drills or practice techniques to solve that issue. Remember you aren't merely fixing a mistake. For example, if your passage is uneven because your fourth finger isn't crossing under properly, then you can work on that particular skill, the crossunder. This will not only work to fix the mistake, but by actually solving a bigger problem, a weakness in your technique, it will help to prevent other errors resulting from that same weakness.
If you believe your mistake is a symptom of lack of knowledge or familiarity, then you will need practice techniques such as saying the note names, or you may need to identify chords or look for patterns in the passage. Whatever technique you use should be focused on learning exactly what you need to do at every moment in that spot, and then using that knowledge each time you play it.
This part of the process is simple; practice using the techniques you identified. I have an "equation" that I use to help remind me of what I need to do for these techniques to be successful.
Targeted Practice Techniques x Attentive Practice over Time
Having chosen the best practice techniques you must practice them with attention (no zoning out or thinking about your grocery list!) and you must expect results over a span of time, rather than instantly. Work through this third step carefully, and you will see your mistake disappear but probably not overnight. Be patient and persistent.
As you get your problem spot more in control, you will need to fit it seamlessly into the context of the piece. Practice creating smooth transitions into and out of that spot, maintaining focus and control as you play. Most importantly, don't fall back into the same mental habits you had before. Think through your solution each time you play to help you get the full benefit of all the work you have done.
Of course, fixing a mistake isn't a forever thing, no matter how intentional you are about solivng the problem. The good news is that once you have done this work, it is easy to go back to step three, work your techniques and refresh your solution.
That's my prescription!