iternabe I looked a bit more into Brent Gillespie. He is a professor of mechanical engineering. The chapter on piano was part of his PhD thesis on how to create a digital synthesizer (or digital piano) .....
One of his concepts is to reduce the mechanism of playing the piano to "mapping". In beginner piano learner's term, I understand this as "if I do this move, I will get that sound"
I'd first want to know whether he plays the piano, and plays it decently. I would not take advice from this kind of write-up but I would listen to someone who has taught a lot of students, worked with these things, observed, and so on. I was once gifted an old hard cover book written by Matthew who proposed that the actual piano playing actions happen deep inside, and intricately. Two people who externally do the same gesture may get different results because what is happening internally isn't the same. Conversely, two people who look very different may be doing the same thing inside and get the same results. (Something like that.)
I once watched a teacher on-line demonstrating certain motions which the students carried out. Later in a recital you could see those motions, but the expected sound from those motions didn't appear. Imagine someone throwing a ball and releasing it; someone else having their arms copy the same trajectory but they are not whipping their arm forward with body follow-through the same way. What is happening inside?
Or, stir coffee and then pudding with a spoon. Your hand and its senses interact with the feeling of viscosity of the liquid, and makes umpteen tiny motions and adjustments. Try doing the same thing, first thinking of "necessary hand motions", all the angles, the greater energy needed against the pudding as opposed the coffee. You'll probably be clumsy when you weren't before, and maybe tense up from the effort. What role does the feedback from your senses play? Here we have the weight of the spoon, resistance from the liquid, and even the familiar sound of clinking may guide the action.
Just spontaneous thoughts. 🙂