Tom-tom is a musical instrument that belongs to the drum family. Most tom-toms consist of a cylinder with a thin sheet of plastic or calfskin called a head stretched across the top, bottom, or both. The tom-tom measures from 6 to 18 inches (15 to 46 centimeters) in diameter and stands from 6 to 20 inches (15 to 51 centimeters) high. It has a dull, hollow sound and may be tuned with a drum key, which adjusts the tightness of the heads. Musicians play the tom-tom with felt mallets, drumsticks, or with their hands.