'OM' is the primordial sound and everything emanated from "Om".
Following "Om" are the vowels, consonants, other syllables and speech. This concept is described by Saint Thyagaraja in his Kriti "Naadhasudharasa" in Arabi raga. Muthuswami Dikshitar describes this in his Navavarna Krithis & Othukaadu Venkata Subbayar describes this in his Kamakshi Navavarna krithi.
Ancient treatises describe the connection of the origin of the Swaras or notes, to the sounds of animals and birds and man's effort to simulate these sounds through a keen sense of observation and perception.
The Sama Veda which is believed to have laid the foundation for Indian classical music, consists of hymns from the Rig Veda, set to musical tunes which would be sung using three to seven musical notes during Vedic Yagnas. The Yajur-Veda which mainly consists of sacrificial formulae, mentions the veena as an accompaniment to vocal recitations. References to Indian classical music are made in many ancient texts, including epics like the Ramayana and Mahabharata
Carnatic music, as it is today, is based on musical concepts (including swara, raga, and tala) that were described in detail in several ancient works, particularly the Silappadhikaram, and Bharata's Natya Shastra. This music system was prevalent in Tamil Region of South India in ancient days. It had no specific name mainly because it was the only music form then. Later it spread to all other Telugu, Kannada and Malayalam regions, undergoing changes in musical aspects and became a southern music. It gained a name when Maharashtrian Kings who patronized this music, named it as ' Karnatak' (Anglicized 'Carnatic') relating it to their immediate border region Karnataka where musicians came from.
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