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 percussion mallet, 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. A wide variety of sticks are used, including wooden sticks and sticks with soft beaters of felt on the end. In jazz, some drummers use brushes for a smoother, quieter sound. 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, or in the case of harder rock music genres, many 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. The shell almost always has a circular opening over which the drumhead is stretched, but the shape of the remainder of the shell varies widely. In the Western musical tradition, the most usual shape is a cylinder, although timpani, for example, use bowl-shaped shells. Other shapes include a frame design (tar, Bodhrán), truncated cones (bongo drums, Ashiko), goblet shaped (djembe), and joined truncated cones (talking drum). Drums with cylindrical shells can be open at one end (as is the case with timbales), or can have two drum heads, one head on each end. 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. On some drums with two heads, a hole or bass reflex port may be cut or installed onto one head, as with some 2010s era bass drums in rock music. On modern band and orchestral drums, the drumhead is placed over the opening of the drum, which in turn is held onto the shell by a 'counterhoop' (or 'rim'), which is then held by means of a number of tuning screws called 'tension rods' that screw into lugs placed evenly around the circumference. The head's tension can be adjusted by loosening or tightening the rods. Many such drums have six to ten tension rods. The sound of a drum depends on many variables—including shape, shell size and thickness, shell materials, counterhoop material, drumhead material, drumhead tension, drum position, location, and striking velocity and angle.