My Mom Padmasani writes the following:

Arvind, I had written extensively about the Hindustani and Karnatak systems for this blog, but unfortunately the whole thing was lost as an unsaved document due to some error and I lost interest in redoing it. Because seldom does it come out as the same. Since you are not forgetting it, let me try again. By the by I am too small a person to give any verdict on Hindusthani vs Karnatak.
-Padmasani

Hindusthani Music and Karnatak Music systems an Analysis

This is exclusively my view on the History of Indian Music after sustained research for so many years. It is time that we understand the core India and its ethos and unite together as Bharatvasis than fragmenting ourselves on a hundred thousand issues. It is time that we appreciate anything which is nice for the sake of its being nice rather than this vs. that or that vs. this. -Padmasani

Before going into the study let us know the meaning of these two very Indian terminologies.

Hindu means the knowledge system that prevailed in India. Sthan means the place. So Hindusthani Music means the music of the place where the Hindu system of knowledge prevailed.

And Karnataka can be interpreted at least in two different ways. a) Karnataka means of the people and the country they inhabit. b) Karna means ear and the old. Ataka means, that of the teacher- which means the karnaparampara or the aural tradition handed down from guru to pupil as an unhindered chain.

When the western authors like Day or Popley interpreted our music they called the music of the south as that which prevailed in the Deccan plateau. Unfortunately the sons of our soil prefer to go by the western authors on our music rather than probe the simple meaning from a Sanskrit dictionary. J

Anyway if you probe History there were only two distinct writers in Indian Music who could be traced as the earliest. They were Bharata and his Natyashastra and Ilango Adigalar who wrote the Silappadikaram. Both wrote amazing details about music and dance. Ilango also relates astrology with music. It is interesting to know that a man from a Royal Kingdom from the extreme south and a man from the extreme north have thought on identical lines. To them both, music was an umbrella term encompassing drama, dance and music. Anyway that shows the Aryan and the Dravidian cultural heritages as highly evolved. By and by the Dravidian tradition of the south was swallowed by the advent of Naik and Marattha Kingdoms. The dominant Telugu and Marathi literature and art forms took sway with which the music of the south also took a tumultuous turn. The Tamil music was replaced by the Aryan form with the Kannada, Telugu and Marathi regional musical and linguistic influence.

The north was no exception to this change. The Mughals brought a fair deal of influence of their own over our music. While the classical art form remained more or less the same, there were other forms like ghazals etc. which came into vogue. North also moved from Dhrupad to Khayal over the period of time. But it retained the originals intact. The music was intact in terms of predominantly creative and not set music.

To trace the textual origin, between Bharata (Natyashastra) and Sarngadeva (Sangita Ratnakara) the music was one Indian Music. By and by the bifurcation started to take place into two different styles of music. While the North retained the original Hindu Music which is raga oriented, the south adapted itself to a confluence of more than one regional influence. Now the music of the south was more lyrically emphatic and descriptive of a theme or subject. It is because the Harikatha was a famous musico-discourse form; the Bhajana Paddati with Radha Kalyana Mahotsav was of a thematic nature. The Kriti form itself served a multipurpose of being used in the above art forms than sailing as a pure musical entity. But one can not refuse that the Kriti form has served as archives of southern raga format. The kriti pool in each raga consolidates the scope of that raga under grammatical peripheries and aesthetic exuberances.

This will be evident if you would analyse the Dhrupad and the Ragam Tanam and Pallavi forms. They are similar.

In dhrupad style the tanam singing is kept alive and the pakhavaj almost equal to our mrdangam was the percussion accompaniment. Khayal is a form with akar alap and tan developed into a more attractive form with tabla as accompaniment.

This much on the short historical side of the two styles of Indian Music. The rest in a later blog.