It’s less about the tuning of the piano itself than the knock on effect it has on the pianist. Even if the audience can barely tell the difference, the pianist themself certainly could, as could the conductor!
Tuning the instrument may well have had a large effect on the audience’s experience overall, because the pianist will play much better on an instrument they enjoy playing—it’s a totally different experience hearing someone perform while they’re enjoying their own art, vs someone who’s distracted by an annoying F# that sounds slightly off in every scale.
Loved the essay; had a surprisingly negative emotional response to seeing what feels like unnecessary cruelty to poetry at the end though!
The act of taking someone else’s poem, changing a mere three words of it (in a way that is both unnecessary and aesthetically detrimental) and then crediting oneself as the author feels icky.
Would the unbastardised verse from Invictus by Henley himself not have worked here?
“It matters not how strait the gate, How charged with punishments the scroll, I am the master of my fate I am the captain of my soul.”