Development of Indian classical music can be ascribed to the time when the nomads and other tribal groups inhabited the regions. Sometimes it is also believed that music existed even before the appearance of human beings or for that matter, even before appearance of living beings on earth there was music. This was the music of the spheres known as the Nada Brahma or Anahata Nada. In fact, there is rhythm and harmony at the root of all creation. Therefore, though music in India originated as part of religious rituals, it gradually assumed spiritual and mystical significance. Music went on to receive a central role in human existence rather than serving as a part of religious rituals. The highest level of practice of music is called Nadopasana (worship of God as primal sound). Thus music was considered to be another route to attain Godhead. This belief forms the metaphysical basis of all the Indian classical music systems i.e., Hindustani, Carnatic or of all regional Sastrik music systems.

Indian Classical Music in Ancient India
During the time of Bharata (5th century B.C. to 3rd century A.D), the system of Indian classical music was very much developed. In Bharata`s time the Murchana used to play the role of modern Thaats or Melas and Mela Kartas, so as to determine the correct structure of the Raaga. He has expounded the full significance of the term Jati by means of its ten essential characteristics-Dasa Lakshanas. After Bharata Muni, Matanga, a great musicologist, wrote a treatise known as `Brihadeshi` around 8th century. He has mentioned the word `Raaga` in his treatise. About the same time, Narada wrote `Nardiya Shiksha` which gives a description of the seven Grama Raagas. Sarangadeva of Sangit- Ratnakara has described the Raaga in detail and furnished complete information regarding the same.

It is Amir Khusru who introduced Persian melodies in Indian music. He made a significant contribution to Indian music, especially Hindustani music, by giving the Indian Raaga a Persian air. Lochana Pandit, the author of `Raaga Tarangini`, has given a description of the Raagas of Hindustani classical music. He has given a detailed chart of Shuddha and Vikrit Swara in his text. Lochana for the first time left behind the old traditions of Grama, Murchana and Jati-Gayana and gave place to the Janya-Janak or the Mela theory. The system of music given in his book is very similar to that which was being practised in the Northern system of music. `Chaturdandi Prakashik` of Punditt Vyankatamukhi was written about the Shaka year 1560. He first introduced the twelve notes system and seventy two Melakartas in the south.

Indian Classical Music during Later Medieval Period
The later medieval period, particularly, the seventeenth and eighteenth centuries, was crucial period for the history of classical music in India. Muslim Singers adopted the music of Hindus and gave a Persian tinge to it. At the time of the advent of Muslim rule almost all the books were mainly in Sanskrit. Though the Muslims did not have knowledge of the language, they developed an interest in it. The local dialect of north was used in some songs as an effective medium of expression. Some Sanskrit Prabandhas or Bandish were translated into Braj bhasha. Thus, the Muslim singers sung the Prabandhas according to their understanding of language and style. The Mughals contributed widely to Hindustani classical music.

Indian classical music has progressed rapidly. It outgrew the concepts of Grama and Murchana. So also Jati, Tan and Alankara enlarged their dimensions. Jati was a primary scale selected from Murchanas for its melodic virtues. It was classified as Shuddha and Vikrit according to its notes. Taan was a simple musical phrase that developed later into elaborate Sancharis for the demarcation of Raaga. Taan assumed a new role in the 19th century. With some differences the two branches of classical music came into existence. Hindustani developed in the northern regions of the country, while Carnatic music as indigenous music continued in the south. The bifurcation of the basic music probably took place after the Muslim invasion. The changes developed during the period between 7th and 13th century A.D. and the two systems materialized eventually. Both systems follow Natyashastra and Sangita Ratnakara. North Indian Classical Music was influenced by foreign forces and underwent great changes in its style while south Indian music kept the ancient system almost intact as it was not much disturbed by foreign invaders. Even so, both the systems have assimilated many progressive streams and style while retaining their core substance.