I believe strongly that once someone is able to play any piece of written music with absolute confidence—with music—learning to do the same from memory is the icing on the cake. However, music is best learned in sections, so memorizing may be a dynamic part of the learning process almost from the beginning, since some sections may be mastered, with music, almost immediately; for those who must perform from memory, getting started as early as possible is the best idea.
The only objection I have to memorization, ever, is that many students attempt to use it instead of reading. In the beginning, working out tiny sections in slow-motion and then accelerating them, using only memory, may seem logical. But it destroys reading, and in the long run learning new music, either with music or without, takes longer.
Here are the the things I say to students, and they are based on what I do to memorize myself.
- Break up all pieces/compositions into sections. Find out which sections are hardest. Learn the hardest section first, then learn the next most difficult sections right afterwards. You can begin memory at any time. Memory actually begins after the first reading, so it is a problem of bringing what you already know “to the front”, where you are conscious of what you have learned.
- If a section seems too long to master, break that section into more sections or “sub-sections”. Again, any section or sub-section can be played from memory at any time. You choose when.
- Mark the sections in the score. Same idea. Play sections with and without music.
- Make absolutely certain that you have chosen the very best fingering for each section.
- The best fingerings for hands separate and under tempo (not full speed) often do not work at all, hands together, at tempo (full speed).
- Test fingerings by playing very small parts, sub-sections; try to play through them as close as possible to the speed they need to go when the performance is finished. This will ensure that fingerings in fast passages will work at full speed. If not, a great deal of slow practice will result in something that will not ultimately work, and time is wasted, bad habits are learned, etc.
- Analyze the music as much as possible. Look for all scales recognizable scales, chords, and other skills.
- Find anything that appears two or more time and is identical. Exact repeats are free bonuses.
- Find anything that appears two or more times and is almost identical but has some tricky changes. Those changes need to be identified, because they will confuse the mind otherwise.
- Find anything that is the same but transposed. For instance, the first movements of most sonatas show the secondary theme twice—usually the first appearance is in another key, most often the dominant—while the repeat (secondary therme in the recapitulation is usually in the key of the movement (tonic).
- What is most difficult will change as time goes by. For instance, the most difficult part at the start may become the easiest (if it is absolutely nailed), while something else that seems easy in the beginning may become hard when a composition is almost finished (polished and nearly ready for performance).
- Wake up the mind over and over again by combining different sections, starting at different spots, etc.
- Most important, summing up: at any time you may memorize any section or any sub-section. You may combine what you have memorized in any way you wish, and before you play something from memory in front of people, you should be able to start at any point, without music, that you are able to start with music.
The ability to memorize is not fixed. Some people find it easy, some a bit hard, some very difficult. But it can always be improved.