Is The harpsichord is incapable of crescendos and diminuendos?

Yes, the harpsichord is generally considered incapable of true crescendos and diminuendos because it produces sound through plucking strings rather than striking them, which limits dynamic control. Unlike the piano, where the player can vary the force applied to the keys to achieve dynamic changes, the harpsichord's volume remains relatively constant regardless of touch. Some expressive techniques, like varying registration or using different stops, can create a semblance of dynamic contrast, but these do not equate to true dynamic shaping.