Which of the following is NOT a keyboard instrument?

The piano is a well-known keyboard instrument that produces sound by striking strings with hammers when keys are pressed. It is characterized by its wide range and dynamic control, making it a staple in many musical genres.

The organ is another keyboard instrument that generates sound through pipes or electronic means when keys are pressed. It is commonly used in churches and classical music, emphasizing its role as a staple in keyboard instrument families.

The harpsichord is a historical keyboard instrument that produces sound by plucking strings when keys are pressed. It was widely used during the Renaissance and Baroque periods, solidifying its place among traditional keyboard instruments.

The clavichord is a lesser-known keyboard instrument that produces sound by striking strings with tangents when keys are pressed. It allows for dynamic expression and was popular in the late Renaissance and early Baroque periods.