How is a piano different from a harpsichord?

The primary difference between a piano and a harpsichord lies in their sound-production mechanisms, which fundamentally affect their dynamic capabilities.

• Sound Production: In a harpsichord, the strings are set in vibration by plucking them with a plectrum made of quill or leather. In contrast, a piano produces sound through percussion; when a key is pressed, a felt-covered hammer strikes the string and then rebounds.12
• Dynamic Gradation: The harpsichord is incapable of varying its volume based on the player's touch; it cannot produce the subtle changes from soft to loud that define the piano's expressiveness. The piano was specifically developed by Bartolomeo Cristofori in the early 18th century to allow for this dynamic range, which is why it was originally called the pianoforte (meaning "soft-loud").13
• Complexity: While a harpsichord relies on a system of jacks to pluck the strings, the modern piano features a highly complex action containing thousands of parts, designed to facilitate rapid repetition and precise control over the force of the hammer strike.45