Ever heard of the U of Iowa Piano Pedagogy Project?

That is indeed very impressive!

Another example, kind of similar but opposite approach is the Let’s Play Piano Methods YT channel. It has 6000+ videos, all done by one old guy. His philosophy is to teach how to play each piece in the method books, but do not show a polished play through so that the students do not attempt to copy him.

I still look for other demo performances of the pieces I learned, to verify and to learn about interpretations. Occasionally, YT surprise me: teach demo contains mistakes, while some student’s own recordings were more wonderfully accurate and artistic. Thus, the quality recordings like those from U of Iowa are indeed a truly valuable resource.

I've gone there a number of times when a piece I was working on was featured by them. One of the pianists there is a PW member who used to post a lot in PW under a pseudonym. I think I remember his name is Jason Sifford, and I especially like his playing. He seems to hit the sweet spot in making it musical but allowing students room for creating their own interpretation.

It has been around for a time. I listened to some pieces back when I was doing method books. It's kind of a no muss, no fuss presentation, which is fine for the purpose.

What I wondered was if they simply sat down and played the pieces, almost the equivalent of sightreading them, or if they did several takes. Probably some of both.

Ithaca Tiffany Poon's sight reading video came to my mind because it's the only one that I have come across that's showing someone sight reading brand new material. BTW she is not a teacher. I also don't recall she mentioning any deliberate effort to target her sight reading ability. So my impression is this is just what a talented professional pianist of her age range can do.

Annique Göttler did some 1 minute, 10 minute, 1 hour challenges on pieces she never learned, but those are popular pieces that she must have heard and be familiar with.

I also watched and collected some very good video on how to sight read, or how to build the skill to sight read, but they don't contain demonstrations.

Ithaca That was indeed entertaining to watch. I recognized the 2nd piece from the French movie “Amélie” - one of my favorites.

Ithaca For your entertainment, here's someone (who probably teaches at a higher level than most), sight-reading pieces of increasing difficulty:

Yes, that is one of the most impressive demonstrations of sight reading ability I've seen online. Tiffany Poon said she's not a good sight reader in one of her videos, and while I envy her sight reading ability, she's correct imo that it isn't special compared to her peers. However, her ability for imagining the sound, for audiation, seems to be extraordinary, which also relates to memory.

Ithaca An aside: is it just me, or is there something weird about the way she holds her fingers? I watched the video 3x and kept trying to Zoom in on her fingers, and it seems as if when she's in "neutral" some of them straighten out and even curl up a bit at the last joint. That tendency seems very newbie-like. (I just googled her; she's definitely not a newbie , so now I'm wondering if she's coming back from an injury or something - I can't recall ever seeing these sorts of finger-flares in people who played seriously.)

This was a very interesting observation, and I've been thinking about it. In short, I think a large part of the reason why she does that here is because she's playing really easy, lyrical music. Often, when I play really easy music, I move my hands in ways that are not "perfect" just because it's fun and more relaxing that way, and beginners mistake that for me being unable to be more efficient, when it's more like how you sway from side to side when taking a leisurely stroll. Also, what she's playing here is all lyrical stuff, and she's kind of "preparing" the key press, almost massaging the keys. That extra air time of the fingers followed by a more deliberate press can give you more control and allow you to play with a better sound. Also, I do think that people's hands and fingers are different and people have harmless "quirks", sometimes you end up practicing a certain thing a certain way for 5000 hours and by that point it's more convenient to just let it be than to fix it (for example, fifth finger raising and so on) because you only have so much time and it's not really getting in the way. Her fingers are rather high for neutral and do bend backwards maybe a bit more than they should, but it's hard to tell from a video like this one. A lot of Asian schools emphasize more high finger action, which also might be playing a role here but it's hard to say.

What I recommend is looking at videos where the pianists are actually tasked with something technically difficult, because that forces them to be as efficient as they can be. Here's Tiffany Poon playing a more challenging piece. Do you see the same things you saw in the other video?

Ithaca But it’s like she’s playing with the pad of her fingers - even in some very speedy sections it looks like she’s curling the last joint

I'm wondering if it's mainly due to anatomical variations, including hand size and hypermobility? Some of the chords look too big to be played in any other way than with her fully extended hands which forces the use of the pads rather than the tips. Could it be more efficient to sometimes keep roughly the same hand shape even when relaxing the hands in-between those stretches? And if her finger joints are hypermobile perhaps she can't help the outermost collapsing in those instances?
Obviously I'm just speculating and my abilities are nowhere near playing that piece myself.