Paragraph 1: Drum is a member of the percussion group of musical instruments. Drums are the world's oldest instruments, and the basic design has remained unchanged for thousands of years. Drum may be played individually, with the player using a single drum. Others are usually played in a set of two or more all played by the one player. A drum is a musical instrument which produces sound by the vibration of a stretched membrane. Drums are part of the larger category of musical devices known as percussion instruments. Drums exist in a wide variety of shapes and sizes. The two basic shapes for shells are bowls and tubes. Drums are usually played by being struck. In modern Western music, most drums are designed to be played by being struck with various devices known as beaters. Some drums, particularly in non-Western cultures, are played in ways other than being struck. Drums are either tunable, so that they produce a particular note, or non tunable.