Ernst:
Yes, I am available to do virtual teaching, as we are playing virtual organs.You can email me even a virtual file, i.e. a midi-file, which I can play back here, although mp3's are fine as well.
Then you get my critique in written form, or if you wish, over the phone. I live on the US East Coast, so that's my time zone.
YouTube is both a great and terrible place, because there are both fine performances of organ music and horrible ones; so I will need to guide you there in the proper direction. I am great believer in LRPA:
1. L = Listening- should come first - gets you familiar with the piece. Of course me must use caution while listening, as some performances are just plain wrong.
2. R= Reading the score, while listening, or if you can hear it in your head while reading it, but at any rate, understanding the music by studying the score. Also, we must use caution that we have an accurate (or the best possible) edition of the music (e.g. an English Voluntary of the 18th century with pedal lines is a bad edition).
3. P = Playing it; this comes last, unless you are already are so well versed, have an easy enough piece in front of you, or are so thoroughly familiar with the composer's style, that you might just as well play this new piece, as it seems so familiar and similar to whatever else he/she or their contemporaries composed.
4. A = Art of Registration. With Hauptwerk, we can often match the music to the organ. Historical organs can teach us directly how to approach the music. It will be good to know which sample sets you have. This is very important for the art of registration. Balance of sound is important. We also need to always make historically informed decisions and learn to adjust that to organs that are different. I believe that the organ determines what types/styles of music it can handle and what not. Forcing a piece of music unto an organ for which it is really not suited strikes me as foolish (and yet happens all too often). The greatness of Hauptwerk is that we do have choices of organs and is actually thus a great learning and discovery tool as well!
Enough said! Hope you come onboard, virtually!