Try these two experiments on your piano…
Experiment #1. With your dominant hand, play any two-note chord, that is a comfortable interval, with your thumb and little finger. Maybe a 5th or 6th or if you have a larger hand, an octave. Play the chord repeatedly, with a loose wrist. Pay attention to how your hand absorbs the shock of connecting with the piano keys, and how quickly it recovers to a relaxed hand position. The better your piano technique, the faster it will relax.
Experiment #2. Stretch your hand to its maximum and do the same thing. You might be playing an octave if you have a small hand, and you might be playing an 11th or 12th with a large hand. Play the chord repeatedly. Observe how your hand absorbs the shock of connecting with the piano keys and most importantly how quickly it recovers to a relaxed hand position. Also observe if your wrist is as relaxed as it was in the first experiment.
When I do these experiments (with my small hand), I notice a quick recovery and a loose wrist in experiment #1 and no recovery with a tense wrist in experiment #2. I predict you will too but please, try it for yourself.
If you have a small hand (can barely reach an octave), you can practice as much as you like but you will NEVER be able to have the fast supple piano technique that a larger hand achieves on regular sized piano keys. You can study with the top piano pedagogues in the world, and you still won’t have a fast supple piano technique for the major piano works. It is an impossible physical feat.
A small adjustment in the width of a piano key makes the impossible... possible. It allows all hand sizes to have access to playing the beautiful piano literature that we all love.
What more is there to say?
by Linda Gould "Let's paint the world with chords" BMus, ARCT, RMT