Theru Koothu is a widely popular folk dance of Tamil Nadu, being more common in the northern part of the state. It is usually conducted during the Tamil months of Panguni, i.e. mid-March to mid-April, and Aadi, i.e. mid-July to mid-August. Theru Koothu commonly occurs during the village festivities and become the centre of all fun, frolic and attention of the folk people. Performed in important junctions of the villages, where three or four streets meet, Theru Koothu takes place in open air, under the gas lights. A wooden bench is mounted up to seat the singers and the musical troupe. In Theru Koothu make-up and costumes are considered to be of prime importance.
Theru Koothu does not allow the womenfolk as performers. Only men can take part and even the female roles are played by the men folk. The performance consists of story-telling, dialogue-rendering, songs and dance, all skillfully managed by the artistes as an individuals as well as a group. Thus the artistes should have versatile performing ability, and has to be multi-talented. The episodes in Theru Koothu are often from the Mahabharata, Ramayana or other Puranic Texts. The tale is interspersed with music and the actors dance using very simple rhythmic stepping as they perform.
The actors perform in a very theatrical manner. They deliver their speeches in high-sounding and sometimes even exaggerated words. They have to be loud enough to catch the attention of the spectators through their voice only as there is no support from modern day microphones as such. Their costumes glitter and words thunder to the accompaniment of the necessary music. The Theru Koothu actors have to be highly innovative to establish rapport with his audience. The performances are so appealing that the villagers are mesmerized under its spell and the long hours just flow by, even past the midnight.
Koothu can be categorized as Nattu Koothu, including Vali Koothu and Kuravai Koothu. Samaya Koothu showcasing religious topics and Pei Koothu including Thunangai Koothu and Porkala Koothu dealing with martial arts are very popular. Taken as a whole, the Theru Koothu of Tami Nadu has always remained essentially an institution of learning through entertainment for the people in general.