The Early Period [2000BC – 1100AD]
Drawing from the roots of the music in the vedas, the interest in arts expanded into other aspects of artistic expressions which included dance and drama. ‘Natya Shastra’ is the earliest known text in Sanskrit to systematically document the evolution of arts during this time. It consists of 6000 sutras [stanzas] organized into 36 distinct chapters. It is also widely believed that sage Bharata is its author, and approximately timed around between 2BC-2AD. Here the author discusses two types of music.
- Gandharva – Music with strict grammatical rules.
- Gaana – Grammatically more liberal form of music.
Eventually, many centuries later, it was the ‘Gaana’ form of music that evolved into ‘Marga Sangita’. This form of music continued to evolve and later towards 900AD, further evolved to a codified art form that was simply called as ‘Sangita’. Later on it may have given rise to another form of music known as ‘Deshi Sangita’ A key distinction to note here is that the term Sangita in Deshi form was more leaning towards music while during the “Marga’ period it included both music and theatre.
Among many important contributions, Natya Shastra introduces the key concept of ‘Shruthi’ as notional sounds contained within seven swaras in an Octave. According to Bharata, Shadja has 4, rishaba 3, gandhara 2, madhyama 4, panchama 4, dhaivata 3 and nishada 2 for a total of 22 shruthis (pitch) within an octave, discernible to human ears. 
Note: Some historians believe that the composition ‘Natya Shastra’ is a work of several persons under the generic name Bharata. It has been suggested that Bharata may be an acronym for the three syllables: ‘bha’ for bhāva (mood), ‘rā’ for rāga (melodic framework), and ‘ta’ for tāla (rhythm). However, in traditional usage Bharata has been iconized as muni or sage, and the work is strongly associated with this personage.
Roughly in the same time period of Natya Shastra, ‘Dattilam’ was another pioneering work authored by sage Dattilla which is dedicated to ‘Gandharva’ form of music. Taking it into one level higher in formal definition, Datilla categorized the melodic structures into eighteen groups called ‘Jaatis’ which are fundamental melodic structures. The Jaatis may have laid the foundation for the future evolution of the concept of ‘Raaga’ as we know today.
Brhaddeshi is yet another important classical Sanskrit text dated somewhere between 6th to 8th century attributed to sage Matanga. Besides clarifying several terse statements in Natya Shastra, Matanga muni, for the first time, speaks about ‘Raaga’ . He formally distinguishes the ‘Marga’ as evolving into classical music and treats the ‘Deshi’ form of music as folk music practiced in those times. Some historians think that ‘Deshi Sangita’ may have evolved from ‘Marga Sangita’. Also Brhaddeshi was the first text to define ‘Adi Taala’ (Rhythm) in the form of one laghu, which is of a different form than what is practiced today as Adi Taala.
Later around late 10th century and early 11th century a great scholar from Kashmir by name Abhinava Gupta wrote a text called ‘Abhinavabhāratī’. It was in the form of a commentary to Natya Shastra.
He was a philosopher, mystic and aesthetician and also considered an influential musician, poet, dramatist, exegete (interpreter of scriptures), theologian, and logician – a polymathic personality who exercised strong influences on Indian culture.
His most important contribution was that to the theory of ‘Rasa’ (aesthetic savour). ‘Rasa’ is a term used to classify Indian classical musical compositions into different categories based on the mood it sets. There are a total of eight ‘Rasas’ identified as shown below with their descriptions.
- Karunaa – Compassion, 2) Shantha- Peace, 3) Veera- Bold, 4) Bhayanaka – (fear) Scary, 5) Raudra- Anger, 6) Vhibatsa – Revulsion, 7) Hasya – Humour 8) Adbhuta – Amazement.
[It is stated that as tradition of Alankara Shastra developed from sixth through tenth centuries, a ninth rasa called ‘Shanthi – Peace’ was endorsed after much philosophical and aesthetic theoritization by Abhinava Gupta. Subsequently the nine rasas were accepted by majority of Alankaarikas and expression of ‘Navarasa’ came into vogue.]