Feel the sharp keys with your fingers. This particular trick might help you to facilitate reading music without looking down. As we all know, the sharp keys are arranged in groups of two and three. For example, by feeling the edges on the left side of the group of two, you can find C, or on the right side – E. Similarly, feel the edge of F sharp and find F, or touch B flat and find B.
If you have to make a leap to some natural note, first try to locate the sharp note which is closest to it. All of this requires that you do not lift your fingers off the keyboard but keep them in contact with the keys at all times. In other words, our hand movements should not be vertical (like at the piano sometimes) but horizontal. Somehow feeling the keys with your fingertips helps you to achieve precision even in leaps. By the way, for managing leaps, I recommend to use the finger preparation technique.
Take a slow tempo. When you practice, I always recommend taking such a tempo that you could avoid making mistakes. At a slow tempo, it is easier to control your movements and to think where each particular note is. If you see a skip in your score, make an appropriate mental note and your finger will respond correctly. At first, your leap might be a little off, but still it would be a leap. If you make such a mistake, it is best not to go ahead and play the piece all the way through. Instead, go back, try to correct this mistake, and play with precision at least three times in a row.
Practice each voice separately. One of the reasons why reading music without looking at the keyboard can be difficult for organists is that they often play all parts (including the pedal line) together. If you struggle with it, obviously, it is too complicated to play the entire musical texture. How can you know if it is too hard to practice for you this way?
Make an experiment – take an organ piece of your choice with or without pedals (it could be a hymn, too). Now try to play it through it once in a slow tempo. If you make more than 3 melodic or rhythmic mistakes in one page, then my guess is either the piece is too hard for you at the moment or you should practice it differently. Instead of playing all parts together right from the beginning, practice each voice separately first. This should be easy enough for most people. Just play the soprano line slowly and count your mistakes. I bet they will not be too many. If you still make more than 3 mistakes in one page playing this way, the piece might just be too complex for you at the moment.
Should you change to an easier piece? It depends. You could try practicing in shorter fragments (perhaps 1-4 measures) at a time. Whether you choose an easier piece of organ music or stick with the current one is up to you. Just try to correct your mistake and play your fragment with precision and confidence at least 3 times in a row.
Later combine them in 2, 3, and 4 voices. After playing each voice has become easy, now it is time to start practicing your work in combination of two voices. Remember not to look down at the keyboard. If the previous step was successful, this combination should not be unreasonably hard either. The next logical step would be to practice in three part combinations and finally, the entire four part texture.
In conclusion, I believe you can be successful at reading your organ music without looking at your fingers. It just takes regular, slow, persistent, and wise practice.
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