Drum

The drum is a member of the percussion group of musical instruments. In the Hornbostel-Sachs classification system, it is a membranophone. Drums consist of at least one membrane, called a drumhead or drum skin, that is stretched over a shell and struck, either directly with the player’s hands, or with a drum stick, to produce sound. There is usually a resonance head on the underside of the drum, typically tuned to a slightly lower pitch than the top drumhead. Other techniques have been used to cause drums to make sound, such as the thumb roll. Drums are the world’s oldest and most ubiquitous musical instruments, and the basic design has remained virtually unchanged for thousands of years. Drums may be played individually, with the player using a single drum, and some drums such as the djembe are almost always played in this way. Others are normally played in a set of two or more, all played by the one player, such as bongo drums and timpani. A number of different drums together with cymbals form the basic modern drum kit.

Drums are usually played by striking with the hand, or with one or two sticks. In many traditional cultures, drums have a symbolic function and are used in religious ceremonies. Drums are often used in music therapy, especially hand drums, because of their tactile nature and easy use by a wide variety of people. In popular music and jazz, “drums” usually refers to a drum kit or a set of drums (with some cymbals), and “drummer” to the person who plays them. Drums acquired even divine status in places such as Burundi, where the karyenda was a symbol of the power of the king. Drums with cylindrical shells can be open at one end (as is the case with timbales), or can have two drum heads. Single-headed drums typically consist of a skin stretched over an enclosed space, or over one of the ends of a hollow vessel. Drums with two heads covering both ends of a cylindrical shell often have a small hole somewhat halfway between the two heads; the shell forms a resonating chamber for the resulting sound. Exceptions include the African slit drum, also known as a log drum as it is made from a hollowed-out tree trunk, and the Caribbean steel drum, made from a metal barrel. Drums with two heads can also have a set of wires, called snares, held across the bottom head, top head, or both heads, hence the name snare drum. 

The second biggest factor that affects drum sound is head tension against the shell. When the hoop is placed around the drum head and shell and tightened down with tension rods, the tension of the head can be adjusted. When the tension is increased, the amplitude of the sound is reduced and the frequency is increased, making the pitch higher and the volume lower. The type of shell also affects the sound of a drum. Because the vibrations resonate in the shell of the drum, the shell can be used to increase the volume and to manipulate the type of sound produced. The larger the diameter of the shell, the lower the pitch. The larger the depth of the drum, the louder the volume. Shell thickness also determines the volume of drums. Thicker shells produce louder drums. Mahogany raises the frequency of low pitches and keeps higher frequencies at about the same speed. When choosing a set of shells, a jazz drummer may want smaller maple shells, while a rock drummer may want larger birch shells.