Dolak
Dolak or Dholak is a barrel-shaped two-headed Indian percussion instrument. Dolak is mainly a folk instrument widely used across many parts of the country. The instrument consists of two heads, one for treble and one for bass. Dholak is an atonal instrument, lacking tuning to any particular pitch although the two heads may be tuned at an interval of fourth, fifth or an octave.
The smaller surface of the dholak is made of goat skin for sharp notes and the bigger surface is made of cow skin for low pitches, which allows a combination of bass and treble with rhythmic high and low pitches. The bass head played usually with the left hand, has a compound ‘syahi’ to lower the pitch and enable the typical Dholak sliding sound (“giss” or “gissa”), often the caked residue of mustard oil pressing, to which some sand and oil or tar may be added. Traditionally, the two heads of the Dholak have been held in tension by a continuous interweaving rope around the shell. In this case, small rings can be found on the rope near the smaller side, which can be used to adjust the tone of the instrument. However, Dholaks with heads fitted using bolt nuts are becoming extremely common.
Dholki or Naal
A variant of the Dholak with a narrower shell, producing sharper tone. The smaller head of the Dholki is pre-tensioned and has the black compound at the center to produce a sharp sound. The bass head is similar to that of the Dholak, but in some cases, it may have the black compound on the outside, with a braided rim, similar to that of a Tabla.
Dhol
Dhol is a larger variant of the Dholak and is found widely across the country with variations. The typical sizes of the drum may vary slightly from region to region. In Punjab, the dhol remains large and bulky to produce the preferred loud bass. In other regions, dhols can be found in varying shapes and sizes and made with different materials such as wood, fiberglass or steel.