or kettledrums
Large bowl-shaped drums with pedal mechanisms for altering their pitch by changing the membrane's tension.
The timpani are the principal orchestral percussion instruments. Each drum usually has a range of a fifth; they are classically used in pairs. Until с 1800 each drum was tuned to a single pitch (usually tonic or dominant) that could not be altered in performance. Primitive kettledrums, or naker s, were played on horseback by Middle Eastern cavalry. In Europe they were primarily associated, in tandem with the trumpets, with court ceremony and the military. They entered the orchestra in the mid-17th century.
Modern timpani with pedal-controlled tension
By courtesy of Ludwig Industries, Chicago