Udgitha Vidya is the art of worshiping the three-syllable omkara. It has been expounded in Brahmasturabhashya and Chandogya Upanishad. It is the second part of Samaveda. Omkara is recited with musical intonation and, therefore, udgitha. The Tamil hymns of Nammalvar are considered an illustration of udgitha vidya.
The body of udgitha is bhakti (devotion) and the vidya is to be initiated by a guru for its success. The origin of udgitha is said to be as follows – Bhutarasa (the flavor of five elements) produces prithvirasa (earth). This results in aparasa (water) as the base. Ausadhirasa is generated from water and represents medicinal plants and herbs. This, in turn, creates purusarasa (the Supreme Being), leading to vakrasa (speech). This leads to rkrasa (hymns or verses), leading to samarasa (soothing life). This emanates udgitha, the cream of Sama Veda.
Sages like Angirasa, Brihaspati, and Dalbhya are said to have practiced this vidya by breathing good air, speaking only good words, seeing only good things, hearing only good words, thinking and doing only good deeds, leading to a good life. These are the basic requirements for the practice of the omkara (udgitha) vidya.