Udgata (उद्गाता)

Maharshi Vyasa instituted the procedures for yagnas that are administered by four kinds of priests. The Brahman priest played an important role in the performance of rituals and maintained the continuity, integrity and purity of the rituals, helped by three other types of priests, the Hotri, Udgatri and Adhavaryu. The Hotri or Hotri priest initiated the rituals by inviting the gods to the ritual place with the chanting of the Rigvedic hymns.

The Udgatri priest sang melodious hymns of praise and invocations from the Samaveda and kept the ritual place ready for the descent of the gods. The Adhavaryu priest was responsible for the performance of the ritual proper according to the established procedure. He chanted hymns from the Atharaveda and with his knowledge ensured that the offerings were made correctly to the gods.

The Brahman priest was responsible for the overall success of the ritual. He carried out supervisory and expiatory functions and acted as the binding thread between the external and internal aspects of the ritual.

Chandogya Upanishad

The Chandogya Upanishad (4.16.1) mentions two methods to perform sacrifices, "by the mind and by speech." Of them, the Brahman priest performs it by the mind and the other is performed by the Hotri, Adhavaryu and the Udgatri priests.