Читать книгу Theory and Practice of Piano Construction - William Braid White - Страница 6

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The pianoforte of to-day is the most complex and ingenious of musical instruments. With the possible exception of the pipe-organ, there is no existing tone apparatus that combines within itself the product of so many varied industries. Both as to the raw material and the finished parts, this instrument draws its tonal charm, in the ultimate analysis, as much from the saw-mill, the machine shop and the iron foundry as from the forest and the mine. Trees of the forest, ore from the mines—even the wooly coats of the peaceful sheep—alike contribute their share to the completion of the wonderful product of musico-mechanical ingenuity that we recognize in the modern pianoforte.

In such circumstances as these, it is easy to understand that the commercial production of these instruments is a formidable undertaking. To the musical and technical skill that is essential must now be added large capital and a great manufacturing plant. The moderate prices at which it is at present possible to sell pianofortes would not be maintained for a moment without this modern system of productive concentration and distributive expansion. The application of such business systems to the production of an essentially artistic structure has had the double effect of cheapening the selling price and improving the quality.

This is not the place to go into details of the organization of a modern pianoforte factory, but we may very properly devote some moments to a consideration of the main points of construction that are observable in the pianofortes of the day. Critical analysis of these points will be in order later on in the course of the present work. For the moment we shall be content with obtaining a bird’s-eye view, as it were, of that which we are later to dissect and criticise.

There are to-day two distinct and prevailing types of pianoforte. These are the “upright” and the “grand.” Of the once popular “square” it is unnecessary here to do more than say that the type has passed into a state of obsolescence and is fast dying out. Both structurally and tonally, it was most defective; and its popularity was due rather to the imperfect development of the other types during the period of its vogue than to any inherent advantages of its own. It has well and faithfully served its appointed time, and we may properly leave it to die in peace.

For the last thirty years in this country and for considerably longer in Europe, the upright, succeeding the square as a home instrument, has remained victorious. Its small size and great convenience, together with the surprising tonal capacity that has been developed in it in the United States, have universally commended it, and only the development of the very small grand has lately seemed to be threatening its long unchallenged supremacy.

The exterior form of an upright is familiar to all. If we strip from it all the outer appendages, and then remove the action and keys, we shall at once see that the instrument consists essentially of a sound-board and a frame, the latter partly wooden and partly metallic, upon which are stretched strings of regularly graduated lengths and thicknesses. Attached to this framing are two more or less ornate wooden erections which are denominated the “sides” of the instrument, while a horizontal wooden shelf, called the “key-bed,” serves to join the sides and support the keys and their frame.

The strings of an upright are arranged vertically from the top to the bottom of the framing already described, with the exception of those which serve the bass notes. These are strung diagonally over the treble strings. It will also be observed that the strings become progressively shorter as the scale ascends until the speaking lengths at the highest notes are two inches or less. The thickness also varies directly as the length. The material of which the strings are made is cast-steel wire, and the overstrung bass strings are, in addition, covered with copper or iron wire. These strings, in order that they may be maintained at the proper tensions and in the correct positions, must be supported by suitable framing. The demands of modern construction require that the framing be most massive. We have already cast a hurried glance at it, and may now proceed to describe it in more detail. First of all, however, it is necessary to investigate the apparatus that amplifies the sound waves projected from the strings and transforms them into the pleasing tones of the pianoforte. We must, in short, examine the sound-board.

We shall have occasion later, critically to examine and discuss the resonance apparatus of the pianoforte. It is sufficient, therefore, that we glance briefly at it here, so as to familiarize ourselves with its general form and construction. The sound-board is usually constructed of a sheet of spruce fir of varying thickness and arched inwards towards the strings, the crown of the arch being at its middle portion. It carries wooden bridges, over which pass the strings and upon which the vibrations of these strings are impressed and which serve to limit their speaking lengths. The side of the sound-board, remote from the strings, is strengthened by the addition of a series of strips of hard wood called “ribs,” which are tightly glued on to it.

All of this apparatus is fitted into a wooden frame technically called the “back.” It consists of two horizontal beams, situated at the top and bottom of the instrument and joined together with a number of vertical wooden posts of great strength. Into this structure the sound-board is secured in such a manner as to produce the arched shape above described, and in such a manner also as to leave nearly the whole of its surface free to vibrate. The top beam of the back is covered with the “wrest-plank,” a wooden block built up of crossed strips of hard maple into which are driven the tuning pins, or “wrest-pins” as they used to be called.

The whole structure is then covered by the “iron plate,” which is a massive affair cast in one piece and bolted all round to the sides of the sound-board and back, and to the wrest plank at the top and the bottom beam at the bottom. This plate contains the “hitch-pins,” over which are looped the waste ends of the strings, and also the iron bridge, which limits the upper extension of their speaking lengths. The strings are arranged upon this elaborate foundation, looped over the hitch-pins, passed over the sound-board—or “belly”—bridges, and thence through the bearing-bar, up to the tuning-pins.

To the sides of this structure are glued the external walls. A wooden bed for the keys is provided, and the action is secured partly to the iron plate and partly to the key-bed. The pedals are placed upon the bottom board, which is secured between the external walls or sides, and the pedals are connected with the proper parts of the action. When this has been done the construction of the instrument is essentially completed.

The various kinds of upright pianoforte do not vary greatly in size. In the United States the popular sizes vary between the extremes of four feet ten inches and four feet in height, with sufficient width to accommodate the eighty-eight notes that make up the modern compass of seven octaves and a minor third. The multitude of different scale arrangements need not be discussed here at all, nor is it necessary to enter into any investigation of the various individual arrangements and devices that different manufacturers fit to their instruments. All these things will be treated in their proper order.

The grand pianoforte has always been the favorite of the composer and the interpretative artist. In this type alone has it been possible to combine the highest qualities of tonal beauty and mechanical ingenuity. To-day the concert grands of our most eminent makers stand unsurpassed, both as mechanical structures and as musical instruments.

The most obvious dissimilarity between the grand and the upright is, of course, seen in the difference of their planes. The grand might properly be called the horizontal pianoforte. Its strings are stretched parallel to the plane of the floor and the hammers strike upwards at them from below. The second conspicuous difference is in the function of the exterior casing. We have already noted that this part of the upright is chiefly required to complete the exterior ornamentation of the structure, and secondarily to support the keys and action. The case of the grand, on the other hand, is an essential part of the resonant body of the instrument. It consists of a rim, bent to suitable shape and built up of continuous veneers, running all round in one piece and glued together at crossed grain until the desired number of layers and the proper thickness are thus obtained. The whole of what corresponds to the upright back framing, as well as the sound-board and iron plate, are rigidly built into this continuous bent rim, and thus the whole structure forms one complete resonant entity, entirely unified and interdependent. The rim is made deep enough to permit of the insertion of action and keys in the front portion, and a gap in the framing is left for the hammers to strike upwards at the strings. The wrest-plank is placed on one side of the gap and the sound-board occupies the remainder of the space on the other side. The iron plate covers the entire structure, wrest-plank included, and sustains the same relations to the instrument as in the upright. Its shape, as also that of the sound-board, is adapted to the peculiar outline of the grand, which is so aptly implied in the word “fluegel” (wing), used in Germany to designate the entire grand type.

Until a comparatively recent period the large concert size grand was practically the only type of these instruments. The revolutionary improvements initiated by the Steinways in the middle of the nineteenth century paved the way, however, for the general introduction of smaller styles. It was found possible to retain the characteristically full and rich tone of the large grand—at least to a great extent—while its inherent advantages in the matter of touch and action all combined to assure the popularity of the smaller instrument among the more critical and discriminating of the public. Doubtless, also, the remarkable change in the housing of urban populations that has been so conspicuous during the last twenty years had much to do with the general desire for an instrument that should be less common than the ordinary upright and that should at the same time be less cumbersome than the full-sized grand. A powerful incentive was therefore given to manufacturers to strive towards the perfecting of the small types, and we cannot deny that they have succeeded in a remarkable manner.

It is true that there exists today a tendency to cut the size of these small grands down to really impossible proportions. There is a limit to the cutting down process; and it is apparent to the observer that more than one maker is endeavoring to obtain a true grand tone from a sound-board area and from string lengths that are such as entirely to prohibit the attainment of this desirable goal. Of course, it may be retorted that the term “true grand tone” is subject to variations of definition. It may even be plausibly said that tone of any kind is too intangible a thing to be limited by any definitions. Nevertheless, it would seem that there is a very decided limit, and that when we arrive at the point where it is no longer possible to obtain the fullness, richness and volume of tone that we are accustomed to accept as the distinguishing characteristic of the grand pianoforte, then, indeed, we no longer have a true grand. Other instruments may have the outline and the action of a grand, but if they have not the proper sound-board area and string length, then they are merely (if we may perpetrate a bull) “horizontal uprights.”

The very general description that we have thus given of the two prevailing types of pianoforte has not been intended to serve as more than what it so obviously is—a rapid bird’s-eye view of the instruments as they appear to the casual observer. The reader may thus prepare himself for the more definite and critical investigation that is now about to be begun.