In the year 1711 Bartolomeo Cristofori, a Florentine, made the first piano, that is to say, an instrument the strings of which were struck by hammers operated by means of a keyboard. That the volume of sound so produced would be soft or loud in accordance with the pressure brought to bear on the keys by the player gave the instrument its name--_Piano_(soft)-_forte_(loud). The harpsichord, it will be remembered, did not offer the player such a chance for expression and for the gradation of sound. The clavichord was inferior to the new instrument in volume and resonance. However, sixty years of experiment and invention were required to bring the pianoforte to the point at which it began wholly to displace its predecessors in the favor of composers and virtuosi. Of the many difficulties which manufacturers had to overcome, only a few need be mentioned. The most serious was the problem of making a frame strong enough to resist the tension of the heavier wire strings. This was met by tension bars, by metal braces, and finally by the invention of a cast-iron frame, not, however, until after Beethoven had ceased writing for the pianoforte. The problem of the action was complicated by the necessity for the hammers to fall back instantly from the strings as soon as they had struck them. This falling back is known as the escapement, and it was chiefly by devices of escapement that two great pianoforte actions came to be differentiated from each other by the end of the eighteenth century. These actions are known as the Viennese and the English. With the former are associated the names of Stein and Streicher. It was a light action and the tone of the Viennese pianos was correspondingly light and fine. It had little volume and in melodies was sweet and clear but not full. It was for such pianos that Haydn and Mozart wrote their sonatas. Both men first acquired their keyboard technique on the harpsichord, and later both naturally adopted a piano the light action of which demanded approximately the same sort of touch as that which they had already mastered. A style of music developed from the nature of the instrument which was little different from harpsichord music. Effects of fleetness and delicacy marked it.