I will proceed in order.
Frank wrote:In my opinion, what matters is not what I know (or you/we) know today, but what someone who is 10 years old knows when faced with Bach's two-part inventions (but also good Bartók... I mention Bach just for the sake of it) and a Czerny étude of equal difficulty. That is where the discussion started.
One should start by saying that, as children, any Bach Invention is just as much a thorn in one's side as a technical exercise, simply because it is used in the same way as a technical exercise. (Then, mind you, you are talking to me about "Bach's Inventions and Czerny studies of equal difficulty," but the discussion did not start there at all, because to find a Czerny study of similar difficulty to a Bach Invention, I have to stop at the first piano master and disregard both op. 299 and op. 740). Let us assume anyway that a child has a distorted perspective regarding what is beautiful, what is useful, what is boring, what is beautiful and useful, what is useful but boring, etc. You say that:
Frank wrote:to appreciate Bach's two-part inventions I don't need to listen to (and understand) The Art of Fugue as conversely I can observe that (it comes through in your writing, but I might have misunderstood) to understand the value of a Czerny study I must know his entire discography
but in my opinion you should specify that to appreciate Bach's Inventions today I don't need to know ADF, because if you tell me that to appreciate the two-part Inventions at ten years old you don't have to listen to ADF, I tell you that even if you listened to it at ten, you wouldn't understand it in the same way that at ten (or fifteen) you don't appreciate the musical value of an étude, simply because you have to die over it to get it, until you hate it. But aside from all this, it is necessary to make a distinction between Bachian pedagogy and Czerny's, a distinction that may seem superfluous, but not even that much. Bach does not write to improve the student's "fluid technique," or at least, that is a consequence and, in any case, the technique of Bach's era had not yet reached the levels of virtuosity of the technique a century and a half later... the final destination of Bach's didactic compositions is to forge a complete musician, who understands expressiveness, who understands counterpoint, who knows how to sing with their fingers and differentiate voices using appropriate articulation. I mean that there is no "school of speed" in Bach, so one should not compare, for example, Czerny's op. 740 with the Inventions, which should instead be related, I don't know, to Debussy's Études, perhaps those from the second volume... while Czerny is something a bit more unto himself, because technique is effectively isolated and writing an étude on chords (just an example) is in any case something that does not leave much freedom (in this regard, even Debussy didn't write exactly a masterpiece, I am referring to Étude XII - pour les accords). In any case, what I meant when I said that Czerny should be appreciated for more than just the études was not that if I know Czerny's symphonies, "The School of Speed" automatically seems like a masterpiece to me. The point was twofold, namely: Czerny is not just études and technique, but also concertos, trios, sonatas, and symphonies; furthermore, listened to with today's ears, the études seem much less "horrible" than they seemed to me when I had to force them down my throat, willing or unwilling...