[1.II.10] Gravity Drop, Chord Practice, and Relaxation
Learning to play accurate chords is the first step in applying the chord attack. Let's practice the above LH CEG chord. The arm weight method is the best way to achieve accuracy and relaxation; this approach has been adequately treated in the referenced books (Fink, Sandor) and therefore will be discussed only briefly here. Place your fingers on the keys to play CEG. Relax your arm (the whole body, actually), keep your wrist flexible, lift the hand from 5 to 20 cm above the keys (the shorter distance in the beginning), and just let gravity drop your hand. Let the hand and fingers drop as a unit, do not move the fingers. Relax the hands completely during the drop, then "set" your fingers and wrist at the time of impact with the keys and let the wrist flex slightly to take the shock of landing and to depress the keys. By letting gravity lower your hand, you are referencing your strength or sensitivity to a very constant force.
It may seem unbelievable at first, but an under-weight 6-year-old and a gargantuan sumo wrestler dropping their hands from the same height will produce sound of the same loudness, if they both perform the gravity drop correctly (which is not easy, especially for the sumo wrestler). This happens because the speed of gravitational fall is independent of mass and the hammer goes into free flight as soon as the knuckle leaves the jack. Physics students will recognize that in the elastic limit (billiard ball collision), kinetic energy is conserved and the above statements do not hold. In such an elastic collision, the piano key would fly off the fingertip at high velocity, like a golf ball bouncing off a concrete floor. But here, because the fingers are relaxed and the fingertips are soft (inelastic collision), kinetic energy is not conserved and the small mass (piano key) can stay with the large mass (finger-hand-arm), resulting in a controlled keydrop. Therefore, the above statements hold as long as the piano is properly regulated and the effective mass for the key drop is much smaller than the mass of the 6-year-old's hand. Stiffening the hand after impact ensures that the entire arm weight transfers to the key drop. Do not stiffen the hand before hitting the bottom of the keydrop because this will add force – we only want gravity to play the keys.
Strictly speaking, the sumo wrestler will make a slightly louder sound because of momentum conservation, but the difference will be small, in spite of the fact that his arm may be 20 times heavier. Another surprise is that, once properly taught, the gravity drop may produce the loudest sound that this youngster has ever played (for a high drop), and is an excellent way to teach youngsters how to play firmly. Start with short drops for small youngsters because, in the beginning, a truly free drop can be painful if the height is too high. For a successful gravity drop, especially for youngsters, it is important to teach them to make-believe that there is no piano and the hand should feel like it is falling through the keyboard (but is stopped by it). Otherwise, most youngsters will subconsciously lift the hand as it lands on the piano. In other words, the gravity drop is a constant acceleration and the hand is accelerating, even during the key drop. At the end, the hand is resting on the keys with its own weight -- this way of playing produces a pleasant, deep, tone. Note that it is important for the key drop to accelerate all the way down - see section III.1.1.2 on producing good tone.
The well-known Steinway "accelerated action" works because it adds acceleration to the hammer motion by use of a rounded support under the center key bushing. This causes the pivot point to move forward with the keydrop thus shortening the front side of the key and lengthening the back side and thereby causing the capstan to accelerate for a constant keydrop. This illustrates the importance piano designers place on accelerating the keydrop, and the arm weight method ensures that we take full advantage of gravitational acceleration to produce good tone. The effectiveness of the "accelerated action" is controversial because there are excellent pianos without this feature. Obviously, it is more important for the pianist to control this acceleration than to depend on the piano.
The fingers must be "set" after the keys reach the bottom of the keydrop in order to stop the hand's downward motion. This requires a brief application of force to the finger. As soon as the hand stops, remove this force and relax completely so that you can feel gravity pulling the arm down. Rest the hand on the key with only this gravitational force keeping the keys down. What you have just accomplished is to depress the key with the least possible effort; this is the essence of relaxation. Note that an important element of relaxation is the immediate relaxation of all muscles once the gravity drop is over.
Beginning students will play chords with too many unnecessary forces that can not be accurately controlled. The use of gravity can eliminate all unnecessary forces or tenseness. It might seem like a curious coincidence that the force of gravity is just the right force for playing the piano. This is no coincidence. Humans evolved under the influence of gravity. Our strengths for walking, lifting, etc., evolved to match gravity exactly. The piano, of course, was designed to match those strengths. When you are truly relaxed, you can feel the effect of gravity on your hands as you are playing. Some teachers emphasize relaxation to the point of neglecting everything else until "total" relaxation is achieved; that may be going too far -- being able to feel gravity is a necessary and sufficient criterion for relaxation. The gravity drop is a method for practicing relaxation. Once this relaxed state is achieved, it must become a permanent, integral part of your piano playing. Total relaxation does not mean that you should always play the piano using only gravity. Most of the time, you will be applying your own force; "feeling gravity" is just a way of measuring your level of relaxation.