Bharatha Natyam is the indian classical dance form originated from the southern state of Tamil Nadu. Basically, it consists of three main elements:
BHA- Bhava, or expression; RA- Ragam, or melody; THA- Thalam, or rhythm; NATYAM means dance.
Originally known as Sadir, Bharatha Natyam existed as a highly evolved temple art form since many centuries and is very complex, including elements of music, drama, poetry, color, and rhythm. In the Hindu tradition,the god Shiva, is the cosmic and supreme dancer
Nataraja. As Nataraja dances, so is created the cosmic energy of the universe. The possibilities that
exist in dance are tremendous and infinite.

http://tribes.tribe.net/bharathanatyam