Wikipedia
The Parai ( Tamil:பறை) or Thappu ( Tamil:தப்பு) is one of the oldest drums used in India, especially in the South Indian state of Tamil Nadu, and also in the northern and eastern parts of Sri Lanka. It is considered as one of the symbols of Tamil culture. In ancient days, this instrument was used as a communication mechanism to convey messages to people and alert against danger. The word Thappu came into practice predominantly during Nayakar's rule in Tamil Nadu. It is believed to be the mother of all skin instruments in Tamil Nadu.
It consists of a circular wooden frame with one end closed with cow skin membrane and the other end open. Thappu is played with two sticks, one being larger and thinner than the other. It is performed in dances, funerals, temple festivals and sport events. Thappu drum or Parai drum is also played to invoke the deities at Madras temples.
Kurunthokai mentions that Parai was used as an auspicious instrument in weddings. It was also used to alert the people in flood time. A type of parai called Ari parai was used in harvest time to make the birds fly off from the fields. Another type of parai called Perum parai is found only in the Kongu Nadu region of Tamil Nadu.
The parai that is played while dancing is called parai aattam (Parai Dance), and is also referred to as Adavu . The parai aattam is a folk art in Tamil Nadu.