Sangam poetry and Tolkapiyam (100-500 AD)
The earliest literary work in Tamil are called Sangam texts. Though, legends place them ten thousands of years back, they were possibly composed during the Pandyan Kings between first and fifth centuries AD Tolkapiyam, belonging to the middle Sangam period, is a Tamil grammatical work, on the lines of Panini's Ashtadhyayi. It is written by a Jain scholar, popularly called Tolkapiyar. Though a grammatical work, Tolkapiyam mentions quite a bit of music related theory. Other sangam works give reference to music, its theory and many musical instruments. The author was aware of Panini and Manu.
The music described was septatonic, with the seven notes termed as kural, tuttam, kaikkilai, uzhai, ili, vilari and taaram. The octave was called mandilam. The 16 Panns mentioned can be compared to Raaga. The parent scales were called Palai, and were seven in number. From these Pallai 103 Panns could be derived. Among musical instruments different types of Yals (lute) have been mentioned.
How much of this was indigenous is difficult to tell. Obviously the Tamil poets were aware of Sanskrit works (like Panini and Manu). They may have also known about Natya Shastra. There were some contacts with the Greeks, known as Yalavanas both in Sanskrit and Tamil works. Not surprisingly Greek, Sanskrit and Tamil works are all septatonic, they talk about 7 notes in music.
Ilango Adigal 's Chilappatikaaram (400-500 AD)
Chilappatikaaram is an old Tamil epic dated before 500 AD Though, music is not the central theme of the epic, there are detailed explanations about the prevailing music and dance in the epic. Thus, it is frequently compared to Natya Shastra, as a basic source of classical music in India. It talks about seven notes, 22 shrutis and several Raagas (called Pan). It also talks about various instruments like the flute and harp (JAl - native Tamil stringed instrument), percussion instruments like mirutangkam (a precursor of the modern Mridangam). Many of the modern Raagas have a corresponding Pan mentioned in Chilappatikaaram.
It is difficult to say to what extent the musical system prevalent at the time was influenced by Natya Shastra. No doubt there was a lot of give and take between the south Indian music and the north Indian even in those days.
Ancient History - Pg 3
Ancient History - Pg 5