quoted from a friend:
"The best way to memorize and defeat performance jitters, is to make sure you've memorized the piece completely. The most difficult works to memorize are undoubtedly the fugues of Bach, and as such makes the best works at practicing memorization. Make sure you've memorized the work in many different ways (endquote" I've inserted some ideas below "quote) and have confidence in yourself. If you KNOW that you've memorized it, and you're confident that you can get through the piece without major problems in memorization, then you stand a much better chance of actually getting through the work. Even if you've memorized it well, as long as you're not confident you can do it, then you WILL have problems."
Some ideas as to ways of memorization:
memorizing the melodic lines (something that everyone probably already does).
memorizing the bassline (something that NOT everyone does).
memorizing the harmony (related to bassline, but subtly different).
memorizing the innervoices (especially in something like a bach fugue).
memorizing the counterpoint between the outer voices (related to the first 3, and again subtly different).
memorizing the structure of a piece (In a sonata form, that would be the different key areas, the transition areas, etc. In a fugue, that would be the different entraces of subjects etc., sequences, how long they go on, how do they get off, etc.)
This is not an exercise in time-wasting or futility. It actually works, but it is very time-consuming.
Jakester