Theory and Practice of Piano Construction / With a Detailed, Practical Method for Tuning

by William Braid White

It is true that the stock styles of grand pianoforte cases are usually plain as to contour and decoration, but no one now can deny to them grace and purity of outline or beauty and richness of material. On the other hand, the practice increases yearly of keeping in stock cases made in such styles as the Chippendale, the Sheraton and the Empire, to say nothing of the perennial and truly American Colonial designs. The fact that these numerous varieties all find purchasers is a striking commentary on the growing taste and refinement of the general public.

In considering the case construction of the upright pianoforte, we are led to observe that this type exhibits, in these matters, certain important advantages over the grand. It is true that the case is not so homogeneously fitted into the resonant structure, and it is equally true that the grand has hitherto had much the better of it in the fight for tonal quality and volume. Nevertheless, considering the upright in the light of its own peculiar fitness for popular use, we are bound to observe, in considering the construction of its case and back-framing, the special advantages over the grand that we mentioned as existing.

The chief and most obvious of the inherent advantages of the upright pianoforte lies in the position which the instrument takes up. The hammers strike in front of the strings and tend to force them down upon the bridges, so that the full energy of the blow is impressed upon them. Further, there is none of that tendency of the strings to fly off from the belly bridge which is always present in the square and to a certain extent in the grand. Again the vertical position of the sound-board would seem to be more favorable to the free vibration of the wooden fibres of which it is composed; while the simplicity of the general outline of the upright permits the employment of a larger sound-board area than is possible with either the square or the small grand. Lastly, the wrest-plank is greatly strengthened by the omission of the gap between it and the sound-board, which permits the use of lighter framing and a consequent gain in portability.

While recognizing these facts, however, we are bound to recognize many other features that go far to destroy the great initial advantage here described. It cannot be doubted that today the upright is pre-eminently the popular type. Whether this fact is entirely a matter for congratulation is doubtful, for the upright form lends itself readily to cheap and trashy production. The conditions of modern domestic life are such, on the other hand, that the portability and convenience of the popular type, no less than the possibility of producing it cheaply, have given it a hold upon the public fancy which its own inherent and undoubted advantages might never have secured for it.

The upright form is capable of the highest artistic and mechanical development, and there is no good reason why it should not be so improved as to produce tones equal in volume, purity and richness to those of the grand.

In considering the details of back and case construction in the upright, we are compelled to observe instances of faulty method. For example, it is usual to fasten the sides of the case to the back by gluing after the latter has been fitted with the sound-board, iron frame and strings. This method is obviously faulty. It is not difficult to understand that, although the back partially sustains the tensions imposed by the strings, the sides when glued to the former are constantly subjected to a modification of these tensions. Now, gluing, while convenient, is not the best possible process to give to the sides the necessary strength to bear such strains, for it is a familiar fact that pianofortes that are not of the highest class invariably develop in the course of a few years, more or less serious cracks and breaks in the continuity of the joins between the glued surfaces. When this happens, the equilibrium of the instrument is disturbed and its strength diminished. In addition, the breaks in continuity have, of course, a serious effect upon the power of resonance. Furthermore, the glue method is subject to various mechanical defects. It is absolutely necessary that the surfaces that are to be united should be maintained, during the process of gluing, at an absolutely uniform temperature. And this temperature must be high. Consequently it is not hard to see that in the haste and confusion of construction in the factory, the large sides and backs may not be so carefully handled as to insure the continual maintenance of the ideal temperature conditions. If, in short, the surfaces to be glued together are permitted to become cold, it is obvious that the adhesion will be imperfect, that the wear and tear of constant usage will complete what carelessness in the factory began, and that the value of the instrument will be permanently impaired.

Before suggesting a remedy for these regrettable conditions, or a substitute for the faulty methods described, it will be well to examine carefully the principles that underlie the construction of the upright pianoforte back. It will thus become less difficult to find some better method of uniting the sides and back, so as better to conserve the strength and durability of the instrument.

The back of the upright pianoforte might almost be considered as the foundation of the instrument. Indeed, before the general introduction of iron framing, this part of the construction deserved such a description. Its position, however, is now somewhat subordinate, since the wooden framing of which it is composed is quite inadequate to the task of supporting the tension of the strings. As generally built, this back consists of a number (usually six) of wooden posts arranged in an upright position and joined at the top and bottom by braces, also of wood and of similar dimensions. Thus is provided a compact frame that may be made to possess great strength and resisting power. But, in order to accomplish properly the duties for which it is designed, the construction of this frame must be very carefully planned and carried out. At its upper end it must give proper support to the wrest-plank and the sound-board must rest easily and securely within its embrace. The iron frame must then be fastened upon and over the structure.

It would be absurd to suppose that the back is not subjected to modifications of the strains imposed upon the sound-board, wrest-plank, and iron frame, and it is equally certain that carelessness in working out the details of construction will tend materially to reduce the coefficient of resistance.

An important detail is the joining of the upright posts to the top and bottom rails. If these rails are made continuous and the posts are tenoned into them, the frame will possess the maximum of strength that is possible to such a structure, and if, in addition, the joints are at all places made more secure by the use of screws and other devices as supplements to the gluing, then we may consider that we have a properly made back.