Cristofori's great success was in solving, without any prior example, the fundamental mechanical problem of piano design: the hammer must strike the string, but not remain in contact with it (as a tangent remains in contact with a clavichord string) because this would damp the sound.
Silbermann showed Johann Sebastian Bach in succession of his early instruments in the 1730s, but Bach did not like it at that time, claiming that the fewer than notes were too soft to allow a full dynamic range. Although this earned him some animosity from Silbermann, the criticism was apparently heeded. Bach did approve of a later appliance he Piano Lessons saw in 1747, and even served as an agent in selling Silbermann's pianos.