[1.III.6.10.2] Photographic Memory
You memorize the entire sheet music and actually picture it and read it in the mind. Even those who think that they do not have photographic memory, can achieve it if they practice photographic memory routinely as they practice the piece from the very beginning. Many people will find that, if they are diligent about this procedure from day one (of when they start the piece), there will be only an average of a few bars per page that are not photographically memorized by the time they can play the piece satisfactorily. One way to photographically memorize is to follow exactly the methods outlined here for technique and memory, but to also photographically memorize the sheet music at the same time, hand by hand, bar-by-bar, and segment by segment.
Another way to approach photographic memory is to start memorizing the general outline first, like how many lines there are in the page and how many bars per line; then the notes in each bar, then the expression markings, etc. That is, start with the gross features, and then gradually fill in the details. Start photographic memory by memorizing one hand at a time. You really need to take an accurate photograph of the page, complete with its defects and extraneous marks. If you have difficulty memorizing certain bars, draw something unusual there, such as a smiley face or your own markings that will jolt your memory. Then next time you want to recall this section, think of the smiley face first.
One advantage of photographic memorization is that you can work on it without the piano, anytime, anywhere. In fact, once acquired, you must read it in your mind, away from the piano, as often as you can until it is permanently memorized. Another advantage is that if you get stuck in the middle of playing a piece, you can easily restart by reading that section of the music in your mind. Photographic memory also allows you to read ahead as you play which helps you to think ahead. Another advantage is that it will help your sight reading.
The main disadvantage is that most people cannot retain photographic memory for long periods of time since maintenance requires more work than other methods because of the high bandwidth of visual images. Another disadvantage is that picturing the music in the mind and reading it is a comparatively slow mental process that can interfere with the playing. However, if you follow the methods discussed here, you may find it much easier than you thought. In principle, once you have memorized a piece, you know every note and therefore should be able to map it back to the sheet music, thus helping the photographic memory. Once you have acquired most of the types of memories discussed here, adding photographic memory requires very little additional work, and you reap considerable rewards. Thus every pianist should use a certain minimum of photographic memory. The first line, containing the key and time signatures, is a good place to start.
For those who think that they do not have photographic memory, try the following trick. First memorize a short piece of music. Once each section is memorized, map it back onto the score from which you learned the piece; that is, for each note you play, try to picture the corresponding note on the sheet music. Since you know every note, HS, mapping it back from the keyboard to the sheet music should be simple. When mapping back, look at the score to make sure that every note is in the correct position on the right page. Even the expression markings should be memorized. Go back and forth, playing from photographic memory and mapping back from the keyboard to the sheet music until the photograph is complete. Then you can amaze your friends by writing down the score for the entire piece, starting from anywhere! Note that you will be able to write the whole music, forwards or backwards, or from anywhere in the middle, or even each hand separately. And they thought only Wolfgang could do it!