2 points:
1. With regard to Auto-Tune: This technology can be used in a live setting. If I understand correctly, a singer's pitch can be corrected instantly, that is, while actually in performance; and the 'correction' is extremely hard to discern if the original pitch error is not overly large. I think most of the pop singers use Auto-Tune in live performance now.
There is no equivalent for playing live piano, as far as I know. That is, there at present no use of any technology which will allow instantaneous, undetectible correction of piano errors of any kind in the course of a performance.
I can picture one, however. In order to understand this, you must know what MIDI is and how it works. In this scenario, the pianist is playing something like a Steinway Spirio, which is a genuine Steinway grand piano; the difference is that MIDI information can actually operate the hammers and dampers, making it a MIDI player piano.
Imagine an app where the music to be played by the pianist (on a Spirio) is also a MIDI score. So the pianist is following an existing MIDI score. The programming is such that no MIDI information will be engaged when the pianist plays exactly the MIDI score. In other words, if the pianist plays 'correctly,' only the real, live pianist will be heard. But if the MIDI score is not followed precisely, the programming will instantly replace whatever is being humanly played (or not played) with the MIDI notes.
So when the pianist follows the score, you will hear the actual live pianist. When he deviates from it, the technology mutes his playing and replaces it with the 'correct' MIDI version as written.
With this principle, a very large range of mistakes might be imperceivably corrected.
(Yes I see at least one potential problem: the significant lapse of time between the player's wrong note, which by definition has already been played, and the MIDI correction. But recall that a key has to travel downward more than a centimetre before the hammer is engaged; that centimetre is more than enough to trigger the sending of MIDI information. Even the velocity at which the key is moving downward is part of MIDI information. So the mistake can be detected BEFORE IT IS PLAYED, during the 'attack' phase, not afterwards. See the excellent GIF of the grand piano's mechanism elsewhere in this forum -
https://www.pianostreet.com/smf/index.php?topic=64233.0or here -
https://imgur.com/F67xGD6I'm no technician, so the whole magilla here is doubtless vastly more complicated and problematic than I can imagine; in fact, just studying this GIF I can see more potential difficulties -- stopping a launched hammer at the last millisecond before impact, pre-empting the damper, etc. But in the end it's all just a question of engineering.)
No spontaneity during performance?
First, the player could be playing a MIDI interpretation that he himself previously recorded, allowing him to express his vision; he could even change his MIDI score before a live performance. So the final result may be a unique, totally characteristic expression of a pianist's individual style and interpretive choices -- only that all those artistic decisions were made before the live performance.
And at the touch of a button, the MIDI circuit could be toggled on or off at any time, to allow a confident pianist to play something spontaneous without fear of interruption from the MIDI player.
2. Lang Lang's injury may be totally cured, for all we know. It is very possible that great advancements have made in the last decade or so in the treatment of such injuries, and Lang Lang can certainly afford the finest in the world. L. Podesta seems to be suggesting that Lang Lang's evil, shadowy 'handlers' will successfully deceive the world into thinking a complete cure has been effected
even if it hasn't. I fail to see how that deception could succeed in the context of a live performance -- and remember that LL will be performing all five of Beethoven's piano concertos next May.
With such repertoire, is it REALLY possible to keep a crippling hand injury secret from live witnesses who are themselves professional pianists?
As this is an extraordinary claim, it requires extraordinary evidence, or at least comprehensive, rational explication. Otherwise it's just 'Web wind' (I just made that up, I think.)
Imagine that LL plays all 5 Beethoven concertos with his usual thundering style or whatever, with no discernible difference from his pre-injury days. If that happens, some will say: "He is successfully hiding his injury." Others, more rational, will say: "There now seems to be no evidence of injury."
Myself, I think a more realistic scenario is that LL has made a partial, even 'almost complete' recovery, and will change his playing style for certain repertoire, so as to continue his career. Most of his legions of fans will not be able to tell the difference, and they won't care what the critics say.
Say what you like about L Podesta. I agree with him at least that this whole issue is very very important. Here's a worst-case scenario: Suppose Podesta is correct that LL's injury is permanent and incurable, AND that he somehow manages to pull the wool over everyone's eyes. What kind of dangerous example does that set for young pianists? The message would be: "Don't worry about piano injuries, they're all curable nowadays! Look at Lang Lang! So mash your chords to your heart's content!"