Indian classical music is principally based on melody and rhythm, not on harmony, counterpoint, chords, modulation and the other basics of Western classical music. The tradition of Indian classical music is an oral one. It is taught directly by the guru to the disciple, rather than by the notation method used in the West. The very heart of Indian music is the raga: the melodic form upon which the musician improvises.
The system of Indian music known as Raga Sangeet can be traced back nearly two thousand years to its origin in the Vedic hymns of the Hindu temples, the fundamental source of all Indian music.
To us [in India], music can be a spiritual discipline on the path to self-realisation, for we follow the traditional teaching that sound is God – Nada Brahma: By this process individual consciousness can be elevated to a realm of awareness where the revelation of the true meaning of the universe – its eternal and unchanging essence – can be joyfully experienced. Our ragas are the vehicles by which this essence can be perceived.
A very brief sample chant and 101 lesson:
There is a saying in Sanskrit – “Ranjayathi iti Ragah” – which means, “that which colours the mind is a raga.” For a raga to truly colour the mind of the listener, its effect must be created not only through the notes and the embellishments, but also by the presentation of the specific emotion or mood characteristic of each raga. Thus through rich melodies in our music, every human emotion, every subtle feeling in man and nature can be musically expressed and experienced.
Ragas are extremely difficult to explain in a few words. Though Indian music is modal in character, ragas should not be mistaken as modes that one hears in the music of the Middle and Far Eastern countries, nor be understood to be a scale, melody per se, a composition, or a key. A raga is a scientific, precise, subtle and aesthetic melodic form.
In terms of aesthetics, a raga is the projection of the artist’s inner spirit, a manifestation of his most profound sentiments and sensibilities brought forth through tones and melodies. As much as 90 percent of Indian music may be improvised and because so very much depends on understanding the spirit and nuances of the art, the relationship between the artist and his guru is the keystone of this ancient tradition.
It is only after many long and extensive years of “sadhana” (dedicated practice and discipline) under the guidance of one’s guru and his blessings, that the artist is empowered to put “prana” (the breath of life) into a raga.
– edited from http://www.ravishankar.org/-music.html by Ravi Shankhar
The article has detailed information on Indian classical music. If you are a musician or student of music, I recommend reading the entire article.