I have greatly enjoyed reading those thoughtful and intelligent quotes from the mysterious teacher: many thanks for taking the trouble to add them to this discussion. Is there much more that could be quoted? Is there any chance that these writings could be published?
Hi michael_c,
and I, in the same manner, enjoyed very much your approach, and your thoughtful writings here.
So I will lead you to the teacher now ( unless not everybody has spotted him yet ).
But let me, finally, add some words myself - I hope I don't disturb jknott's question and further discussion about the bandwith theorem / pulse duration too much.
The most important lessons he gave have been recorded on tape by the Lady you all saw in the video linked above: Elinor Armer. She was his student, and she also typewrote the lessons.
I estimate there are TWO versions of the typewritten material. One of 1974, which I have, in original, because my friend from the USA, who ALSO was student of Elinor Armer's teacher, gave it to me as a present. He just asked me whether I wanted the material - I said "yes". And he sent it via airmail.
Check out the Lady on WP:
https://en.wikipedia.org/wiki/Elinor_Armer and follow the link to her PIANO-teacher. There, you will find the data of the PUBLISHED version of the material ( from 1984 ) . Its title is slightly different from my version.
1984: A comprehensive approach to the piano.
1974: ( my version ): Eleven Lectures on Technique of Practicing, Playing and Teaching Piano
120 pages. typewritten. Loose leaves, ring-bound by hand.
What I don't know, is, in which points the versions would differ. I have spoken about that problem with an accomplished piano professor on another place, but to a clear result he / I havent come either
But what I know, is, that the 1974-version probably is very very rare, because,
NORMALLY, only the direct students of the teacher got it, and since I'm not a direct student of him, but an "exception", because I got it from my FRIEND, who was his student, but not "in common sense" my teacher ( since we only met online for many years, and sent post-packages "over the ocean" with infos, hints, tips, and material, and wrote many e-mails ) , I only can rely on this 1974-version, when quoting him here. The 1984-version I will not try to get. Seems difficult, as well, even if published. ( Arif Press , as you can see ).
And at last, a little "warning" may be appropriate:
As I already pointed out, these lectures, which are - and contain - HIGHLY developed material, contain ideas which for many "schools" are NOT WELCOME, because they can endanger whole (insufficient) concepts existing and taught for centuries. The lectures by the mentioned teacher, who was Petri's student and friend, are, thus, kind of "hermetic", and can be seen as "Last Resort" against unreasonable nonsense. Seldomly you will find people on the web, like myself, who quote from the lectures, because most of them who own the valuable writings, are seemingly of the opinion, that they are more valuable if NOBODY knows about them except the owners.. .
But since my friend - and I, too, - are of a different opinion, - as far as I am concerned, I think: "Information is a rare good: It increases its value, getting bigger, if shared."

- I sometimes quote from them.
People who are interested in the material, should try to get the 1984 versions somehow. Or, if they know somebody, try to get the 1974 version, too and COMPARE them!
But, again: The ideas in the lectures can - and will - lead to hatred by some traditional "schools". That's what we have to include in our thoughts. But the ideas can be of VERY much help, too, and some people will like them very much, too.
My friend from the US, who gave me the lectures' 1974-version, perhaps his OWN specimen (!!), might have thought, that they would fit my OWN approaches very nicely, because, he knew, that I was self-taught ( autodidact ), but was of the opinion, that I got very far. So, he added to what I already had found out for myself, the lectures. And I will be forever thankful to him!!
@Michael_c: I spotted in many postings of you some ideas, which are very close to the ideas in the lectures. So, I would very much recommend to you, that you under all circumstances try to get the 1984 version ( or even the 1974 ). And then..read.. .
________________
But now, I think, jknott had some interesting question to some interesting other facts, so, I stay
with many cordial greetings, 8_octaves!!