The word "timpani" derives from a Greek word that means to strike. The timpani are pitched instruments, which consist of hemispherical-shaped shells of copper or brass, over which are stretched the heads of calfskin. Pitches may be varied by changing the tension at the head by means of the 6 surrounding screws or the foot pedal. The drumsticks of the timpani are usually wrapped with felt or sponge in order to achieve different sound effects.

A modern orchestra usually employs 4 timpani of different sizes and pitches. Besides enhancing the rhythm of an orchestral work, the timpani are also effective as a ground bass.