The modern piano-forte had as its immediate predecessor the harpsichord, the instrument on which the heroines of the novels of Fielding, Smollett, Richardson, and their contemporaries were wont to discourse sweet music, and for which Haydn and Mozart composed some delightful minor works. In the harpsichord the strings were set in vibration by points of quill or hard leather. One of these instruments looked like a piano, only it was provided with two keyboards, one above the other, related to each other as the swell and main keyboards of an organ. At last it occurred to lovers of music that all refinement of musical expression depended on touch, and that whereas a string could be plucked or pulled by machinery in but one way, it could be hit in a hundred ways. It was then that the notion of striking the strings with a hammer found practical use, and by the addition of this element the piano-forte emerged into existence. The idea appears to have occurred to three men early in the eighteenth century, almost simultaneously--Cristofori, an Italian, Marins, a Frenchman, and Schroter, a German. For years attempts to carry out the new mechanism were so clumsy that good harpsichords on the wrong principle were preferred to poor piano-fortes on the right principle. But the keynote of progress had been struck, and the day of the quill and leather jack was swiftly drawing to a close. A small hammer was made to strike the string, producing a marvelously clear, precise, delicate tone, and the "scratch" with a sound at the end of it was about to be consigned to oblivion for ever and a day.