I know a lot of Leslie Howard's recordings from his complete Liszt set are horribly sped up. The example of the original Liszt tenth etude that I wanted to use was banned so you'll just have to trust me.....
I will never forget the comment made years ago by a local wannabe classical radio station presenter. The subject at hand was Maurizio Pollini, and his response was that there is nothing better than Pollini "live."
I have Pollini's recording of the Chopin Etudes, and there is no way this is an un-doctored straight recording. However, in reference to a later point in this discourse (regarding drugs), I have heard Pollini play the Schumann Piano Concerto live on radio wherein he played it so fast that he actually played through the melody.
Returning to the OP's premise, just like the reference I made before to rock n roll, studio recordings for a very long time have been doctored. Glenn Gould had a professional state of the art recording studio at his Estate, and Vladimir Horowitz (Horvitz) had Columbia Records construct one in his spacious New York apartment for his personal use.
With Horowitz, any time he felt like "running some tape," they (Columbia) would put the producer Thomas Frost in a cab and then send him over to record whatever HRH Horowitz felt like recording. After that, if he liked it, then the two of them would argue/fight over the mixing/splicing of the final product.
Next, the untold story is of the Russians/Ukranians, in Contest, juicing a particular performances with methamphetamines. After that, in recital, all of a sudden they do not have all of this magnificent technique.
I tell you what: why don't you compare the recent Piano Street photographs of their favorite female pianist, with her promotional photographs on her website? The point being is that regular users of "Speed" have a certain facial look about them, especially under the eyes.
Go ahead, take a look. In one set of pictures, she looks like a "Babe." And the rest: you decide.
Hey, do you think Rock and Rollers (and "Jazzers" before them) invented this stuff. The fakery, and everything coupled with it, all started with classical performers.