By Hans Schneider
When we consider the popularity of the piano and the fact that it has been in use for several centuries, one would think that a great many vital improvements would have been made, and yet during all this time there has been but one great epoch-making change in the mechanical production of its tone, which was due to the change from tangent to hammer as string irritator or tone producer.
The piano is the lowest instrument in the scale of musical instruments, the most mechanical, the least "musical" from an artistic and emotional point, yet on account of the fullness of its tone, its large range of pitch, its ability to produce the whole score, melody and accompaniment, it is the most musical instrument, the most useful one to the musician as well as to the amateur for the expression of musical thoughts and for the gaining of musical knowledge and literature.
Professor Kullak is reported to have said that "there is nothing mysterious about piano playing." There is never anything mysterious about anything in which the last effect is due to a mechanical device. In such case there is only one law, that of cause and effect, and all other principles are subordinate to this great one.
The part of the piano which is responsible for the tone (the ultimate music) and which is moved and controlled through the keys is a mechanism. It is invisible, and thousands of piano players have sat in front of the wooden board and have played, yet have never seen the mechanism work, and so have teachers who have talked learnedly to pupils about tone production or about touch. The keys which transmit the player's energy to this mechanism are levers, which must be stirred up from their inherent inertia by an outside force.
What this force is, how it is applied is immaterial to the key, but with that proverbial "cussedness of inanimate things" it insists on being treated just so, in order to do its best.
One of the main principles in the understanding of the key action is, that the key must reach the bottom, the keybed, in order to make the hammer agitate the string, and that it will immediately return to its former position when it is relieved from the pressure on its upper level. Equally important for the teacher and student is the full understanding of the reciprocal action between key and hammer.
Of the piano action the hammer is the only part that comes in contact with the tone-producing matter, the string, and is directly responsible for it, and its action is regulated by a number of co-operatively working levers while the human body never comes in contact with string or hammer.
In all other instruments the human body comes directly in contact with the very parts of the instrument which produce the tone. In the string instruments the finger is always, so to speak, on the pulse of the string. In the wind instrument the breath is the very tone producer. Each of these is in closest rapport with our emotional life, constantly influenced by it and parallels these ever-changing feeling states with corresponding physical states, which must naturally show themselves immediately in the tone.
With the hammer is connected a damper, whose action is not productive, but inhibitive, for it prevents the string from vibrating longer than wanted. Key, hammer and damper are always active together, and the understanding of the relations of these actions is most interesting to teacher and pupil.
They are as follows:
When the key is at rest, the hammer is also resting against a felt-covered bar, near the front, about two inches distant from the string in the upright, or two inches below in the grand.
When the key is struck quickly and reaches the keybed the hammer has struck the string, rebounded and is now held stationary halfway between string and bar. The damper is removed about one-half of an inch from the string.
When the key rises again to the level the hammer moves back to the resting board and the damper is pressed forward against the string.
All these parts work forever in different directions, especially the hammer and damper, for when one moves towards the string the other moves away from it.
Each of the individual keys has its own hammer, and the motion of the piano hammer is like the motion of any other hammer.
The hammer is so located and constructed that in order to reach the string it must cover an intervening space "flying," and it is therefore subject to all the laws of flying bodies (ballistic energy), and on account of this flying motion the hammer must therefore receive at the very beginning the full force that is to regulate its speed and power.
But as the distance from the bottom of the key at rest to the greatest depth is but one-quarter of that which the hammer has to traverse, the hammer must move four times as fast as the key.
From the law that the faster a body travels the more power it has, we can deduct the principle that the "softness or loudness" of a piano tone depends entirely and exclusively upon the speed which the hammer develops and therefore also upon the speed with which the player attacks the key.
The speed of the hammer is therefore the only principle involved in the tone production of the modern piano, and no other force can enter into it. Attack, tone and hammer-speed can never be separated, one is bound up in the other, one the consequence of the other. The quicker (more sudden) the attack on the key, the faster the hammer, the louder the tone, and vice versa, the slower the attack, the slower the speed of the hammer, the softer the tone.
But the very quality of tone must also be imparted at the very moment when the finger comes in first contact with the key. It is therefore necessary that the player must be positive as to what kind of a tone he wants long before he actually produces it. If that is not the case, not a "willed" preconceived tone will be the result, but a tone of accidental character, quality and quantity, "any old tone," as is produced daily and hourly by the majority of players.
A player can set a key to motion and produce a tone by either the full arm or any part of it, for piano playing is but "useful labor performed by one body upon another," a matter of kinetic energy. Whatever we do with our arms, hands or fingers after the key has been struck is of no influence upon hammer or tone; but what the muscles do before is of utmost importance.
To make this important action still clearer we can compare the flying piano hammer with a flying baseball, which also leaves the control of the player the very instant it leaves his hand. In whatever direction or manner it is to fly, all this must be decided upon before it starts on its journey, for when it once has started, it is too late to regulate its course.
A hammer once started must finish the way it got started. If the effect miscarries it does so because the effort is miscarried, it cannot be helped for the hammer is helpless and lifeless in itself, it has no more imagination nor feeling, nor music sense than its cousin the key. Quantity and quality of a piano tone are therefore governed by only one force, the initial velocity given to the key by the player.
This indisputable fact will throw light upon many things.
The following little experiment will prove this conclusively. Put your hand or a single finger on the keyboard and strike a key moderately swift. Then increase the suddeness of attack, and you will find that the increase of speed of attack will result in a louder tone, for as the key goes down quicker, the hammer also moves faster towards the string, and therefore generates more power.
Now strike slower and your tone will get softer. But even here in the slowest effort you will find that the last effort upon the key, must have a certain suddenness unless your effort will fail you. Finally you will come to an attack so slow that it does not result in any tone at all.
The fact that no tone at all is produced when the attack gets too slow, is due to the action of the escapement which throws the hammer back again after it has covered half its way and does not allow it to reach the string whatever. When you press the key down very slowly, you will come half-ways to a point where you feel as if a catch was released; this is the end of your control over the hammer, from now on the hammer must either be sent forward to fly or it must fall back. But even if at this point you move quickly you will still get a faint tone, the faintest possible.
The reason for this softness of tone is that if we press the key down half-ways the hammer also has but one-half of its distance to cover and consequently arrives at the string with less force than when traveling the whole distance.
