The Piano Zone
If one could describe the feeling inside a concert pianist's hands, it might be called The Piano Zone. Perfectly limber and loose and prepared for anything. If you’re trying to play the great romantic composers, you’ll need every bit of strength your fingers, arms and shoulders can muster. Without strength and endurance, you may be able to scale one difficult passage. But what about the next impossible passage, and the next one? What if there are dozens or hundreds of difficult spots?
Some piano pieces are like rock climbing. You climb up a difficult face only to find an even more hair-raising one just ahead. Finish that rock face and you think you get to rest? No, there’s the biggest difficulty of all just coming up. Over and over comes that scenario on the page. And truly great music requires gymnastic efforts on the order of Olympic skill level.
Music Composed For Elephants
Rachmaninoff remarked that his Third Piano Concerto was composed for "elephants" to play. He wasn't far wrong. It takes superhuman strength just to endure the physical motions, and that's not counting making a performance with the proper emotional and dramatic qualities. Multiply that scenario times a thousand and you have the difficulties of Schubert’s Wanderer Fantasy, or the Liszt B Minor Sonata. Even to make it through pieces like these is a badge of courage. More than courage, it will take strength. In fact, courage will not really do you any good unless you have the strength.
You're Not Stupid, You're Weak
Many passages that young pianists think impossible simply demand superhuman wrists and fingers. Often, it's not that you are too stupid to play a complex passage, but that you are simply too weak. The old pianist’s saying that you may as well stay home without complete technical command of the piano are basically true. Warm up thoroughly. For me, this takes 45 minutes. At the age of 18, it took 5. The more you play, the shorter this period becomes. Miss a day of playing and it takes several days to get it back to where it was.
Strength Of Mind
After finger strength, you have to cultivate mental strength, to be able to remember not only the music, but the plan of the music, the whole rather than the parts. The theme of the poem, not the words. But to control the music, you have to be in command of it, and to command it you must not be worried about being physically able to produce it. Either you play the piano, or it plays you. Ultimately, the two things must be blended together to produce a fine piano performance. Strength and poetry.