Stodart appears to have preceded Broadwood in taking up the manufacture of the grand piano by four or five years. In 1777 he patented an alternate pianoforte and harpsichord, the drawing of which patent shows the Backers action. The pedals he employed were to shift the harpsichord register and to bring on the octave stop. The present pedals were introduced in English and grand pianos by 1785, and are attributed to John Broadwood, who appears to have given his attention at once to the improvement of Backers' instrument. Hitherto the grand piano had been made with an undivided belly-bridge, the same as the harpsichord had been; the bass strings in three unisons, to the lowest note, being of brass. Theory would require that the notes of different octaves should be multiples of each other and that the tension should be the same for each string. The lowest bass strings, which at that time were the note F, would thus require a vibrating length of about twelve feet. As only half this length could be afforded, the difference had to be made up in the weight of the strings and their tension, which led, in these early grands, to many inequalities. The three octaves toward the treble could, with care, be adjusted, the lengths being practically the ideal lengths. It was in the bass octaves (pianos were then of five octaves) the inequalities were more conspicuous. To make a more perfect scale and equalize the tension was the merit and achievement of John Broadwood, who joined to his own practical knowledge and sound intuitions the aid of professed men of science. The result was the divided bridge, the bass strings being carried over the shorter division, and the most beautiful grand pianoforte in its lines and curves that has ever been made was then manufactured. In 1791 he carried his scale up to C, five and a half octaves; in 1794 down to C, six octaves, always with care for the artistic, form. The pedals were attached to the front legs of the stand on which the instrument rested. The right foot-pedal acted first as the piano register, shifting the impact of each hammer to two unisons instead of three; a wooden stop in the right hand key-block permitted the action to be shifted yet further to the right, and reducing the blow to one string only, produced the pianissimo register or una corda of indescribable attractiveness of sound. The cause of this was in the reflected vibration through the bridge to the untouched strings. The present school of pianoforte playing rejects this effect altogether, but Beethoven valued it, and indicated its use in some of his great works. Steibert called the una corda the celeste, which is more appropriate to it than Adam's application of this name to the harp-stop, by which the latter has gone ever since.
Up to quite the end of the last century the dampers were continued to the highest note in the treble. They were like harpsichord dampers raised by wooden jacks, with a rail or stretcher to regulate their rise, which served also as a back touch to the keys. I have not discovered the exact year when, or by whom, the treble dampers were first omitted, thus leaving that part of the scale undamped. This bold act gave the instrument many sympathetic strings free to vibrate from the bridge when the rest of the instrument was played, each string, according to its length, being an aliquot division of a lower string. This gave the instrument a certain brightness or life throughout, an advantage which has secured its universal adoption. The expedients of an untouched octave string and of utilizing those lengths of wire that lie beyond the bridges have been brought into notice of late years, but the latter was early in the century essayed by W. F. Collard.
From difficulties of tuning, owing to friction and other causes, the real gain of these expedients is small, and when we compare them with the natural resources we have always at command in the normal scale of the instrument, is not worth the cost. The inventor of the damper register opened a floodgate to such aliquot re-enforcement as can be got in no other way. Each lower note struck of the undamped instrument, by excitement from the sound-board carried through the bridge, sets vibrating higher strings, which, by measurement, are primes to its partials; and each higher string struck calls out equivalent partials in the lower strings. Even partials above the primes will excite their equivalents up to the twelfth and double octave. What a glow of tone-color there is in all this harmonic re-enforcement, and who would now say that the pedals should never be used? By their proper use, the student's ear is educated to a refined sense of distinction of consonance and dissonance, and the intention and beauty of Chopin's pedal work becomes revealed.
The next decade, 1790-1800, brings us to French grand pianoforte-making, which was then taken up by Sebastian Erard. This ingenious mechanic and inventor traveled the long and dreary road along which nearly all who have tried to improve the pianoforte have had to journey. He appears, at first, to have adopted the existing model of the English instrument in resonance, tension, and action, and to have subsequently turned his attention to the action, most likely with the idea of combining the English power of gradation with the German lightness of touch. Erard claimed, in the specification to a patent for an action, dated 1808, "the power of giving repeated strokes, without missing or failure, by very small angular motions of the key itself."
Once fairly started, the notion of repetition became the dominant idea with pianoforte-makers, and to this day, although less insisted upon, engrosses time and attention that might be more usefully directed. Some great players, from their point of view of touch, have been downright opposed to repetition actions. I will name Kalkbrenner, Chopin, and, in our own day, Dr. Hans von Bülow. Yet the Erard's repetition, in the form of Hertz's reduction, is at present in greater favor in America and Germany, and is more extensively used, than at any previous period.
The good qualities of Erard's action, completed in 1821, the germ of which will be found in the later Cristofori, are not, however, due to repetition capability, but to other causes, chiefly, I will say, to counterpoise. The radical defect of repetition is that the repeated note can never have the tone-value of the first; it depends upon the mechanical contrivance, rather than the finder of the player, which is directly indispensable to the production of satisfactory tone. When the sensibility of the player's touch is lost in the mechanical action, the corresponding sensibility of the tone suffers; the resonance is not, somehow or other, sympathetically excited.
Erard rediscovered an upward bearing, which had been accomplished by Cristofori a hundred years before, in 1808. A down-bearing bridge to the wrest-plank, with hammers striking upward, are clearly not in relation; the tendency of the hammer must be, if there is much force used, to lift the string from its bearing, to the detriment of the tone. Erard reversed the direction of the bearing of the front bridge, substituting for a long, pinned, wooden bridge, as many little brass bridges as there were notes. The strings passing through holes bored through the little bridges, called agraffes, or studs, turned upward toward the wrest-pin. By this the string was forced against its rest instead of off it. It is obvious that the merit of this invention would in time make its use general. A variety of it was the long brass bridge, specially used in the treble on account of the pleasant musical-box like tone its vibration encouraged. Of late years another upward bearing has found favor in America and on the Continent, the Capo d'Astro bar of M. Bord, which exerts a pressure upon the strings at the bearing point.
About the year 1820, great changes and improvements were made in the grand pianoforte both externally and in the instrument. The harpsichord boxed up front gave way to the cylinder front, invented by Henry Pape, a clever German pianoforte-maker who bad settled in Paris. Who put the pedals upon the familiar lyre I have not been able to learn. It would be in the Empire time, when a classical taste was predominant. But the greatest change was from a wooden resisting structure to one in which iron should play an important part. The invention belongs to this country, and is due to a tuner named William Allen, a young Scotchman, who was in Stodart's employ. With the assistance of the foreman, Thom, the invention was completed, and a patent was taken out, dated the 15th of January, 1820, in which Thom was a partner. The patent was, however, at once secured by the Stodarts, their employers. The object of the patent was a combination of metal tubes with metal plates, the metallic tubes extending from the plates which were attached to the string-block to the wrest-plank. The metal plates now held the hitch-pins, to which the farther ends of the strings were fixed, and the force of the tension was, in a great measure, thrown upon the tubes. The tubes were a mistake; they were of iron over the steel strings, and brass over the brass and spun strings, the idea being that of the compensation of tuning when affected by atmospheric change, also a mistake. However, the tubes were guaranteed by stout wooden bars crossing them at right angles. At once a great advance was made in the possibility of using heavier strings, and the great merit of the invention was everywhere recognized.
James Broadwood was one of the first to see the importance of the invention, if it were transformed into a stable principle. He had tried iron tension bars in past years, but without success. It was now due to his firm to introduce a fixed stringed plate, instead of plates intended to shift, and in a few years to combine this plate with four solid tension bars, for which combination he, in 1827, took out a patent, claiming as the motive for the patent the string-plate; the manner of fixing the hitch-pins upon it, the fourth tension bar, which crossed the instrument about the middle of the scale, and the fastening of that bar to the wooden brace below, now abutting against the belly-rail, the attachment being effected by a bolt passing through a hole cut in the sound-board.
This construction of grand pianoforte soon became generally adopted in England and France. Messrs. Erard, who appear to have had their own adaptation of tension bars, introduced the harmonic bar in 1838. This, a short bar of gun metal, was placed upon the wrest-plank immediately above the bearings of the treble, and consolidated the plank by screws tapped into it of alternate pressure and drawing power. In the original invention a third screw pressed upon the bridge. By this bar a very light, ringing treble tone was gained. This was followed by a long harmonic bar extending above the whole length of the wrest-plank, which it defends from any tendency to rise, by downward pressure obtained by screws. During 1840-50, as many as five and even six tension bars were used in grand pianofortes, to meet the ever increasing strain of thicker stringing. The bars were strutted against a metal edging to the wrest-plank, while the ends were prolonged forward until they abutted against its solid mass on the key-board side of the tuning-pins. The space required for fixing them cramped the scale, while the strings were divided into separate batches between them. It was also difficult to so adjust each bar that it should bear its proportionate share of the tension; an obvious cause of inequality.