Indian classical music during the ancient times

The origin of Indian classical music dates back to the Vedic times and reference of the concept of Nadabrahma is found during this time. Chants and a system of musical notes along with rhythmic cycles are found in vedic scriptures dated 6,000 years ago. Ancient text Samveda,  containing organized music, was structured to melodic themes. In Vedic scripture Samaveda provided the foundation for Indian music. The Samaveda consists of hymns of Rigveda which are set to melodies. These hymns used to be sung using three to seven musical notes during Vedic sacrifices. The Rigveda embeds the musical meter as well. It is believed that the earliest raga originated from Samaveda. Music was purely chanting of verses in musical patterns in the late Vedic period. 

During the ancient times, two musical genres prevailed : Gandharva and Gana. The Gandharva was the formal composed music performed during ceremonies. This music was considered celestial and divine. The Gana was the informal and improvised music performed for entertainment performances. Prabandh Sangeet, a form of music written in Sanskrit, became very popular during the second to the seventh century CE. It is believed that the form of Dhruvapad evolved from Prabandh Sangeet. The ancient classical text, Natyashastra, by Bharat Muni is the foundation of numerous classical music and dance traditions of India. Natyashastra was the first musical work in written format that divided music into octaves and 22 keys. Other two important written works that are worth mentioning are Brihaddesi by Matanga in the ninth century where Matanga tried to define Raag and Sangeeta Makarand by Narada written in the 11th century, describing 93 raags. Raags were classified into feminine and masculine categories in Sangeeta Makarand.