In Ṛgveda (Rigveda), the Ṛtvik (Ritwik; priests) of yajña (yajna) who sings Sāmavedic chants, are called Sāmaga (Samaga). In yajñik practice, the Sāmaga brahmins are defined as ‘Ud’ The sons, sang by these ‘Ud’, in Gāyatrī-Triṣṭubha (Gayatri-Trishthubha) meter, is compared with the song of the kapinjala bird — ‘O bird, you sing like the udgāta — udgāteva śakune sāma gāyasi.

Among the four types of priests, engaged in yājñik rituals, as representative of the four Veda(s), Udgātā is the priest of Sāmaveda (Samaveda). The instruction for chanting hymns during the yajña can be found in Ṛgveda itself.

However, only in case of Somayāga (Somayaga), this Sāmavedic Ṛtvik or Udgāta and his three assistants Prastotā (Prastota), Pratihartā (Pratiharta) and Subrahmaṇya (Subrahmanya) used to sing hymns along with the reading of śastra (sastra). The Ṛk mantra(s) are called ‘śastra’. Before the Hotā, or the priest of Ṛgveda, would start the reading of śastra in Spomayāga (stotramagre śastrāt), the Udgātā would sing the Sāma hymns.

The number of the śastra(s) chanted by the Hotā were equal to that of the hymns sung by Udgātā. Since in Agniṣṭoma (Agnishtoma) yāga(yaga), the yajña would be complete with the singing of the Sāma called Agniṣṭoma, the entire ritual was called Agniṣṭoma. Sāma-singing was not necessary for any other place, so the Udgātā was not required, too. In Somayāga, while extracting Somarasa, the Udgātā used to sing a number of hymns.
In the Sarpasatra of Janamejaya, Kautsa Jaimini was Udgātā, and in the Rājasūya yajña (Rajasuya yajna) of Yudhiṣṭhira, the task of Udgātā was performed by the sage Susāmā (Susama).

In Brahmāṇḍapurāṇa (Brahmandapurana), it is said that God Viṣṇu created Udgātā from yajña —
udgātrādīṃśa yaḥ kṛtvā yajñāllokānanukramān.
According to Matsyapurāṇa (Matsyapurana), the Supreme God created Udgātā from his two arms.

Afer Jamadagni, father of Paraśurāma (Parasurama), was killed by Kārtavīryārjuna (Kartaviryarjuna), Paraśurāma completed yajña and gave the entire northern side to Udgātā as donation.

In the yajña of Vali, God Viṣṇu is conceptualised as Hotā, Udgātā and everything else in one self.

The deed of Udgātā is fulfilled through Sāma-singing — udgātram sāmabhiścakre.