Why did Bartolomeo Cristofori invent a piano?
He invented the piano basically because it was his job. He was employed by Prince Ferdinando de Medici, a lover of music. His job was not only to repair the musical instruments played by the other employees of the prince, but also specifically to innovate, and invent new instruments. The piano was one of the instruments he invented while on the job. It was only one of a number of keyboard instruments — all of them improvements on or innovations from the harpsichord — that he invented. If you are asking why the piano was invented — that is, what makes it better and different from the harpsichord, the harp, or any other stringed instrument, this is a different question. The piano differs from the harpsichord essentially in the mechanics of the hammers that strike the strings. Cristofori’s innovation was that the hammers strike the string but do not remain in contact with it (which damps the sound, as is the case with the harpsichord and clavichord), and the hammer returns to its rest
