In the Natya Shastra – an ancient treatise of performing arts, compiled by Bharat Muni dated 200 B.C.-200 A.D., the musical instruments have been divided into four main categories on the basis of how sound is produced with the help of the instrument.
- Avanaddha Vadya or Membranophones- Percussion instruments
- Ghana Vadya or Idiophones- Solid instruments which do not require tuning.
- Sushira Vadya or Aerophones- Wind instruments
- Tata Vadya or Chordophones- Stringed instruments
Avanaddha vadya are percussion instruments. Such instruments are made by Stretching the animal skin across a metal or earthen pot, wooden barrel or frame. The sound is produced by striking the animal skin that has been stretched across the body. The earliest reference to such instruments could be found in the Vedas. The Vedas have a mention of a hollow pit dug in the ground and covered with a buffalo or ox hide that was stretched across the pit. The sound was produced by striking the hide with the tail of an animal. The main categories under Avanaddha Vadya are- Ankya, Alingya, Oordhwaka and the waisted or the Damaru family of drums.
Ankya drums are covered with the animal hide on both sides. They are held horizontally by the musician and the sound is produced by striking both the sides with fingers or sticks. The musician may sit on the floor while [playing the instrument or hang it from the neck while dancing or standing. Prominent varieties of Ankya that can be seen today are Mridangam, Khol, Pakhawaj etc.
Seals discovered from the Indus Valley sites show men playing horizontal drums hung around their neck.
Alingya drums have the animal hide fixed to a wooden round frame and are embraced or held close to the body with one hand while the other hand is used for playing on the instrument. Under this category, the Duff, Dufflies, etc. are very popular.
The Oordhwaka drums are placed vertically before the musician. The sound is produced by striking the instrument with fingers or sticks. Prominent varieties among these are the Tabla pair, Bayan, Dagga and Chenda.
Damarus are also known as hourglass varieties of drums as their shape is similar to that of an hourglass. The instruments in this category range from Timila of the Southern region to the Huddaka of Himachal Pradesh. The small Huddaka is stuck with the hands while the larger instrument Timila is hung from the shoulders and is played with fingers and sticks.