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.