Dholaks are one of the most widely utilised drums in the folk music of India. They have also found a permanent home in most of the recording and broadcast environments. Applications range from dance music such as bhangra and garba to devotional bhajans and keertans. It is not used for classical music where the tabla and pakhavaj reign supreme.
Dholaks are a double-headed drum with the bass head on one side and the treble head on the other. They are barrel shaped with a single membrane on the right hand side, and a single membrane on the left hand side with a special application on the inner surface. This application is a mixture of tar, clay and sand (dholak masala) which lowers the pitch and provides a well defined tone. The shell or the main body of the Dholak is hollowed out of a solid block of wood, over the two usually equal size open ends of the hollowed cylinder, parchment is stretched by tightening cords of braces, through leather hoops on both sides. To achieve tonal variation between the two heads, generally a past of flour and iron filing is fixed on the parchment of the left side to permanently lower the tension of the left side head.
Dholaks have small circular metal rings, and loop or wooden pieces are passed through the braces which can be pulled on either side. These are used to increase and decrease the tension of the heads. The right head is kept in high pitch and the left head is kept in low pitch. It is struck on both sides by the hands, fingers, knuckles and part of the palm. A metal ring is sometime tapped on the shell of the instrument.
There are two ways of tightening the dholak. Sometimes they are laced with rope, in which case, a series of metal rings are pulled to tighten the instrument. Or metal turnbuckles are employed. It is quite easy to play. There are basically two approaches to the technique - the open handed playing and the controlled finger playing. The open handed technique is much louder that the finger type, but the latter is more articulate.
There are several positions for playing the dholak. The most popular position is to squat with the dholak in front, the bass head to your left and the treble head to the right. Some players sling one of their legs over the centre of the drum barrel to stabilize it. In a Keertan or bhajan situation, it is quite common to have a second person sitting opposite the player with a hard object such as a stick hitting the barrel, thus giving a rhythmic hits somewhat similar to a wood block sound.