Re the recent comments about "challenge" in performance and interpretation ...
Here's what I suspect may be an obscure quote from Glenn Gould that I thought you might enjoy. (If it's in Gould's other writing, I'd appreciate the source.)
1905 to 1913, Edwin Welte set up his ultra-faithful recording/playback
piano system in a castle on the Rhine, and rolls were cut by, among others,
Debussy, Ravel, Saint-Saens, Gabriel Faure, Grieg, Scriabin, Mahler, Richard
Paderewski. They played their own compositions, and those of the dead masters, Mendelssohn, Liszt, Chopin, Beethoven, Mozart. In the text accompanying these performances, a "genealogy" shows how, through generations of teacher-pupil, these recordings retain vestiges of the styles and interpretations dating back to the invention of the keyboard. The Welte rolls provide echoes of the actual way Beethoven and Mozart thought piano music should be performed.
In 1962, a Welte playback machine -- a robot called the Vorsetzer, with 88 fingers and pedal feet that could be rolled up to any piano -- played rolls from the 1905-1913 recordings on Steinway Concert Grand No. 61 in a Los Angeles state-of-art recording studio. They are, essentially, perfect reproductions of all the nuances of the original performances.
Gould commented that the Welte rolls are
"... both enormously rewarding and deeply disturbing ... because many of these performances are hard to reconcile with the architectural notions which our own generation prize most highly ... one is made deeply aware of the transitory nature of interpretative ideals, and one is even led to ask fundamental questions about the nature of stylistic concept as viewed by the performer."
I have more about the Welte player piano at