Membranophone, Percussion Instrument (tuned); The early timpani was used in Eastern military music and was brought to Europe in the 15th century. It was originally performed by the cavalry on horseback and eventually into the orchestra by the 17th century. Originally, pitch was changed by tightening or loostening the threaded bolts around the rim. This was changed in the late 18th century when a handle was fixed to the bolt to allow quicker changing of the pitch. Today, most timpani use a tuning mechanism that is operated by a foot pedal. The singular form of timpani is timpano. Also know as the kettledrums, timpani are made of hemispherical copper (or fiberglass) shells, each fitted with a head of plastic or calfskin which is held in place by a metal ring. A soft or hard padded mallet is used to play them; a pedal mechanism is attached to each timpani which changes the tension of the head, thus adjusting the pitch. The timpani sound is created by striking the membrane, or head, with mallets causing the head to vibrate. The tension of the head determines the exact pitch. A looser tension creates a lower pitch and a tighter tension creates a higher pitch. The timpani comes in several standard sizes with each having a range of about a perfect fifth. The professional models can extend the range up to an octave. Standard sizes and ranges include 20 inch diameter, F3 to C4, 23 inch diameter, D 3 to A 3, 26 inch diameter, A2 to E3, 29 inch diameter, F2 to C3, and 32 inch diameter, D2 to A2.