Ghatam (Kadam), literally meaning a pot, is an instrument of ancient origin ancestor of which is detailed in the Natya Shastra. Ghatam differs from normal clay pots as a special type of baked clay is used for the preparation. Copper or brass fillings with small amount of iron fillings are mixed to the clay to produce the unique metallic sound.
Ghatam is unique in whole array of musical instruments, as all the five elements of nature are found in it. The basic material for Ghatam is mud that represents the holy earth. The mud is mixed with water, baked in fire and the final Ghatam has air inside the belly which reverberates creating the musical sound.
The pitch of the Ghatam is inherent and varies according to its size. As the size of the Ghatam increased the pitch decreases i.e. larger Ghatams have lower pitches. Unlike other instruments the Ghatam cannot be tuned but the pitch can be altered marginally by applying plasticine clay (or other resonating substances such as ravai) and water to the inside of the pot.
The Ghatam has three portions namely the "Vaai", mouth, at the top followed by a slanting "Kaluththu", neck portion, protruding from the mouth and the spherical "Udampu", resonating body portion. The Ghatam sits on a "Vatta Annai", a padded ring
The Ghatam is played with all parts of the hand. Palms are used at the mouth to produce bass notes. Wrist, knuckle, thumbs, fingers and even nails are used on the spherical part.
This instrument is made in number of place in south India, but the ones made in Mana Madhurai are famous for their quality and strength.