How did Bartolomeo Cristofori contribute to the invention of the piano?

Bartolomeo Cristofori, an Italian harpsichord maker, is credited with inventing the piano around 1709. Originally termed gravicembalo col piano e forte ("harpsichord that plays soft and loud"), his invention addressed the harpsichord's inability to vary volume based on key pressure.12

Cristofori achieved this by replacing the harpsichord’s plucking mechanism with a sophisticated hammer action. His most significant contribution was the development of the escapement mechanism. This allowed the hammer to strike the string and immediately fall back, preventing it from rebounding against the string even if the key remained depressed. He also included a check to catch the falling hammer and a system of dampers to silence strings when keys were at rest.12

By 1726, Cristofori had refined his design to include the essentials of modern piano action. Additionally, he introduced a unique double-wall case construction to isolate the soundboard from string tension. While his wooden frames limited the volume compared to modern instruments, his design provided a responsive, wide dynamic range that laid the foundation for the modern piano.12