Mridangam is the classical percussion instrument of South Indian music and is an indispensable accompaniment for musical concerts and dance. The name Mirudangam literally means ‘clay body’- probably because the shell was originally made of clay. The body of the Mirudangam is scooped out of a single block of wood – commonly Jackwood, although Redwood or Margosa wood may also be used. The shape of the body resembles that of two flower pots joined at their rims. Mridangam used of the male is longer and wider, whereas the one used for the female is shorter and narrower.
Mridangam is a tuned percussion instrument with two heads on either side – treble (tuned to the tonic note of the performer) and bass, both separated by an octave. The treble head consists of three concentric layers of skin. The inner layers are made of calf skin while the outer layer is made of sheep skin. The treble head has a circular black fixture, called Karanai or Soru. This black substance gives Mridangam its characteristic tone. The bass head consists of two layers of skin. The outer layer is made of buffalo skin and the inner is made of sheep skin.
The diameter of the treble side is smaller than that of the bass side by half-an-inch. The two heads are held together over the body by means of a leather strap called ‘Var’. By gentle strokes with a small hammer, the pitch of the instrument can be adjusted.