Piano Technique - Theory
5. Characteristics of the keyboard and its mechanical parameters
The images on the right and below (hover with the cursor) show us basically a longitudinal section of the key.
= Key engaged Level A - key at rest, in its upper position; Level B - level of the double escapement, (the mechanism which permits quick repetition). When slowly pressing on a key of a grand piano, one feels at this point a slight supplementary resistance that is not perceived when the key is struck more rapidly, i.e. during a normal strike; Level C - “at the bottom” of the key, i.e. at the maximum depth of its descent; D - a felt pad that reduces the noise of the key against the piano’s key frame.
1 Czesław Sielużycki - “The pianist’s hand” p. 211, Polish Music Edition, Cracow, 1982
2 Op. cit. p. 120
3 Jean-Jacques Eigeldinger - “Chopin: Pianist and Teacher as Seen by His Pupils”, Cambridge University Press, Cambridge 1986
Fig. 1c shows the key fully depressed
IMPORTANT! The pianist can control the movement of the hammer only until the line B, which is about ¾ of the AC depth. The hammer travels “alone” for the last quarter of the way to the string only by the force of its trajectory. At this point, the repeating mechanism breaks its contact with the key (Sielużycki4). Without underestimating the importance of hand’s pressure to the keybed, it must be taken into account that this pressure does not comes until after the beginning of the sound. Conclusion: the sound is produced by the movement of transmission of the units extending from the shoulder to the fingers (“The Bridge”), while an eventual pressure at the bottom of the key only determines the next sound. In practice, this difference is so small that one can not, in principle, account for it. But it is important to understand this succession of movements so as to be able to solve certain particular technical difficulties (see the following).
4 Czesław Sielużycki - op. cit. p. 211
Fig. 1b - the key is pressed only to level B. The keyboard characteristic presented in paragraph 5.2 is used in a special technique that involves pressing the keys not completely to the bottom, but only up to level B, that corresponds to the minimum pressure needed in order to obtain a sound (Sielużycki5). Obviously, this has nothing to do with superficial playing resulting in a poor sound quality. The difference is the amount of energy (mass) used to produce the sound and how to transmit this energy to the mechanism of the piano: a beginning student using only the mass of the fingers, hand and possibly the forearm, produces an uneven and thin sound. On the other hand, an experienced pianist uses the large mass of the entire motor apparatus, so that even his ppp sounds amply. To return to the technique of partially depressed keys: thus, for each note , the pianist can gain between 2 and 3 mm, which, with a speed of about a dozen notes per second, provides a significant economy of energy. Since this technique deprives the hand resting on the bottom of the key, it is necessary to use the inertia of the keyboard. That is why it is the pianos with a „stiffer” keyboard that best allow this technique. This way of playing requires perfect mastery of “hovering” over the keyboard that makes very proficient use of the motor appparatus on two planes: horizontal and above all vertical. So that the sound becomes balanced, all keys must be pressed not only with the same speed, but also to the same key depth.
5 Czesław Sielużycki - op. cit. p. 211
Fig. 1b’ - the key vibrates around the level B’. That is to say, not only it is important not to press the key down to the keybed (cf. the preceding point) but also one must not release it completely so it returns to the resting level A.
|level A||¯¯¯¯¯ = key at rest|
|level B’’||––––– = key at halfway down, but not enough (too high) for repetitions|
|level B’||––––– = key at halfway down: OPTIMAL for repetitions|
|level B||––––– = key at halfway down, but too much (too low) for repetitions|
|level C||_____ = key engaged|
● RH/LH alternating (fastest and easiest option);
● a single finger, permitting the vibration of the entire motor apparatus (the most difficult option - cf. Chapter 10).