After Cristofori’s death, other instrument builders made piano in radically different sizes and shapes, as well as mechanisms unlike Cristofori’s.
Silbermann made improvements on the Cristofori piano based mostly on Johann Sebastian Bach’s criticisms of it in 1736-that the action was heavy and unpredictable, and the tone of the treble too weak. Silbermann introduced the damper stop using hand-stop to the piano. The stop raised all the dampers at once, so that the player could obtain more resonance. When Bach played on Silbermann piano eleven years later at the court of Frederick the Great in Potsdam, he seemed satisfied enough with the improvements made and even signed his name as agent on the sale of a Silbermann piano to Count Branitzky of Bialystok.
Cristofori’s pianos were the size and shape of a harpsichord, though their mechanism was radically different. As the piano became more popular, the piano-makers began to make adjustments to the harpsichord-shaped piano to make it more adequate to new needs.
The square piano was made in 1742 by the German maker Johann Söcher, although it was Silbermann’s pupil Ersnt Christian Friederici who was often credited with its invention. The square piano has a close similarity in appearance to clavichord except for the heavier metal strings, strengthened frame and the hammer action of the former. It was Johannes Zumpe who adopted and popularized the square piano in London.
During the 1770’s, the design of grand pianos took different directions between London and Germany. Since public concerts account more for the professional performance on the piano in London, English piano makers pursued greater power of sound. In Germany and Austria, the piano was mostly performed in courtly gatherings. The Germans strive for greater fleetness and subtlety in the response of the instrument to the player’s touch. Aside from this major difference, there were also important differences in the design of the case, the stops and other features.
The English designers gave their action a direct-blow design instead of Cistofori’s intermediate lever. The action was modified by Robert Stodart in 1777. It was adopted later by John Broadwood in his grands in 1785 and became the standard in English and some French pianos for about one hundred years.
The English grands generally had two stops namely a damper lifter and a keyboard shift or una corda. These stops were activated by pedals which were attached to the front legs of the instruments, with the damper pedal on the right and the una corda on the left. Later the pedals were attached to a frame under the middle of the keyboard.
At about the same time, on the other side of the Continent, Johann Andreas Stein introduced the Stein action which came to be known as the Viennese grand action. This action was lighter, more responsive to touch thus making it more conducive to subtlety of expression than the English action.
For stops, German and Viennese makers used knee levers, tucked inconspicuously under the front of the case below the key board. After 1800, they switched to pedals, after which they also increased their stops, sometimes reaching up to seven. There was a buzzing “bassoon” stop, a muting “moderator” stop, a thumping and jingling military stop among others, aside from the two basic damper lifter and una corda stops.
Both the English and German grand pianos grew in range and size. By the beginning of the 20th century however, piano manufacturers favored the English tradition over the Viennese in action design as well as choice of stops.
Pianists, however, complained that the English action was stiff and could not give rapid repetition. Sébastien Erard, a leading French piano manufacturer, patended in 1821, a design he called “repetition” or “double escapement” action. With Erard’s design, pianists no longer need to choose between the power of the English action and the speed of the Viennese action. This action was improved upon by pianist and piano manufacturer Henri Herz in 1840. It later became the standard in grand piano action.
The upright piano, an up-ended grand, was developed and patented by William Stodart in 1795. Its main advantage was that it does not take up as much floor space as the grand piano. The English upright rested on a stand of table height such that the top end almost reaches the ceiling. The German and Austrian counterpart of an upright was called the “giraffe.” Unlike the English upright, these pianos had cases extending down to the floor, making it more stable with no loss of instrumental quality. At the turn of the 19th century, the stand of the English upright was dispensed with altogether, allowing the instrument to rest squarely on the floor. The early upright was enclosed in rectangular cabinets, with the vacant space within, above the shorter treble strings, fitted with shelves to hold music, books, spirits or knick-knacks.
The upright and square pianos were also being designed to emulate the touch and sound of grand pianos. The upright was built as big as a grand to capture the advantages of its large soundboard, long strings, and the resulting full tone. But the enormous expansion of the piano market in the 19th century depended on the creation of smaller pianos. In 1836, Robert Wornum of London developed the “cottage piano,” which stands less than four feet in height. To fit the strings of a length that would give a decent tone in the shortened case, he hung the strings diagonally. Henri Pape of Paris built an even smaller upright in the late 1820’s, only about 36 inches high. To achieve a tone approaching that of a grand, he devised a scheme of “cross-stringing,” wherein the longest bass strings ran diagonally from lower left to upper right, while the shorter treble strings ran in the opposite direction and the longer ones crossed above the others. The bridge for the lower strings was also located where they would resonate more richly. This innovation was eventually adopted in grand piano design, to make them sound even grander.
Meanwhile, an escapement for square pianos was developed. In 1786, John Geib, patented an action for the square that contained the intermediate lever that made the actions of Silbermann’s pianos so responsive. To keep up with the grands, squares were also built bigger, with wider key boards, heavier hammers, thicker strings, and louder tone.
Early pianos had wooden frames. Pianos of different shapes showed strains of increased tension in different places. Squares tended to warp upwards at the right front and left back corners due to the diagonal arrangement of the strings. Grands, especially the English and French grands, tended to warp at the right cheek, where the case curves inwards. German and Viennese grands tended to warp less because of their sturdy A-frame bracing.
The increased tension on strings brought about by the demand for ever louder sound for pianos, coupled with the ease with which pianos went out of tune, lead to the development of the iron frame to address the need for a stronger frame. Alpheus Babcock introduced the iron frame in 1825. The iron frame is considered to be the most significant development in the history of piano technology. With the iron frame, the string tension could be increased without the accompanying problems as in a wooden frame. But the piano suffered from an unpleasantly metallic tone, even with the improved version of Jonas Chickering in 1840. This problem was overcome with Steinway’s introduction in 1855 of the Overstrung Scale, a system whereby the bass strings crossed over the others in a fan-like pattern. The iron frame was first use in square pianos and then in grands in 1840.
The Overstrung Scale introduced by Steinway to grand piano, was adopted from cross- stringing developed by Henri Pipe. Steinway, aside from cross-stringing, incorporated several previous innovations by other builders and which were pioneered in squares and uprights: Babcock’s one-piece iron frame; the split bridge invented by Broadwood; the felt-covered hammers pioneered by Henri Pape; the agraffe, a method of securing strings at the tuning-pin end used by Erard; and the full present day range of seven octaves. Together, these innovations produced the Steinway sound that set the industry standard-louder, richer and more blended than previous piano sounds. It also became the sound that manufacturers of smaller pianos tried to emulate.
By 1860s, most European piano manufacturers stopped making squares, and the Americans followed their lead by the end of the century. Only the uprights and grands were continued to be produced. Although the grand defined the ideal sound for all pianos, it was the upright that dominate the market