The  reason why Indian classical music sounds exotic to the western  audiences is because of the differences between the two traditions in Tuning and Scales. Indian classical music does not emphasize harmony but sets a greater inportance to melody.The most important point to note is that movements in Indian classical music are on a one-note-at-a-time basis. This progression of sound patterns along time is the most significant contributor to the tune and rhythm of the presentation, and hence to the melody. Although Indian music is now divided into the two major classes of Hindusthani (Northern Indian) and Karnatak or Carnatic (Southern Indian), the origins and fundamental concepts of both these types of music are the same. The form of presentation may however vary between the two systems, as well as from one gharana (family) to another in the former system.  

Both the styles Hindustani and Carnatic are monophonic in nature, follow a melodic line and employ a drone (tanpura) with the help of one or two notes against the melody. Both the styles use definite scales to define a raga but the Carnatic Style employs Shrutis or semitones to create a Raga and thus have many more Ragas than the Hindustani style. Carnatic ragas differ from Hindustani ragas. The names of ragas are also different. However, there are some ragas which have the same scale as Hindustani ragas but have different names; such as Hindolam and Malkauns, Shankarabharanam and Bilawal. There is a third category of ragas like Hamsadhwani, Charukeshi, Kalavati etc. which are essentially Carnatic Ragas. They share the same name, the same scale (same set of notes) but can be rendered in the two distinctively different Carnatic and Hindustani styles. Unlike Hindustani music, Carnatic music does not adhere to Time or Samay concepts and instead of Thaats, Carnatic music follows the Melakarta concept.