The neuter term brahma is used in the Rigveda both in the abstract sense of "devotion, worship," and in the concrete sense of "devotional rite, prayer, hymn."
The Udgatri's duties being mainly confined to the chanting of hymns made up of detached groups of verses of the Rigveda, as collected in the Samaveda-samhita, the more important Brahmanas of this sacerdotal class deal chiefly with the various modes of chanting, and the modifications which the verses have to undergo in their musical setting.
As regards the Brahmanas of the Rigveda, two of such works have been handed down, the Aitareya and the Kaushitaki (or Sankhayana)-Brahmanas, which have a large amount of their material in common.
The Rigveda (3, 8) describes it as a tree well lopped with axe, anointed and adorned by the priest.
In the Rigveda he is represented as the god of prayer, aiding Indra in his conquest of the cloud-demon, and at times appears to be identified with Agni, god of fire.