Carnatic swaras: How are they similar to/ different from Hindustani swaras:

Musical notes are called ‘swaras’ in both Hindustani and Carnatic music traditions. Basically these are 12 musical sound frequencies/ notes that are interrelated with each other and form the basis of the melodic structure of music.

Carnatic theory of ‘swara’ is different from the Hindustani theory of swara. The Carnatic theory believes that there are '16 swara-designations' but only '12 swara-positions' (swara-sthanas). So how does the calculation go? 12 swara-sthanas are generally represented by 12 swaras (that is why the concept of ‘swara’ and ‘swara-sthana’ coincide with eachother in Hindustani classical music). But in carnatic music, among the 12 swara-sthanas, there are 4 swara-sthanas or ‘frequencies’ that are represented by 2 names/ designations. So we now have 4x2=8 notes plus the remaining 8 notes (represented only by one name/ designation) and thus in total we have 16 swaras and only 12 swara-sthanas. In a particular raga (Indian classical melodic form), one swara-sthan can be designated only by one swara-name. So in a raga, a particular frequency is only called by one name even though it has two names. A western music analogy would be calling a key D# or Eb. So the same note/frequency has 2 different names and only one name is used according to the context.

Observe the following table and check the similarities and differences between the theoretical details about ‘sawara’ in Hindustani and Carnatic system:

Swara Position	Hindustani name	Hindustani pronunciation	Hindustani Notation (Roman)	Carnatic name	Carnatic pronunciation	Carnatic notation
1	Shadja	Saa	S	Shadjam	Saa	S
2	Komal Rishabha	Re	r	Shuddha Rishabham	Ri	R1
3	Shuddha Rishabha	Re	R	Chaturshruti Rishabham or Shuddha Gandharam	Ri or Ga	R2 or G1
4	Komal Gandhara	Ga	g	Shatshruti Rishabham or Sadharan Gandharam	Ri or Ga	R3 or G2
5	Shuddha Gandhara	Ga	G	Antara Gandharam	Ga	G3
6	Shuddha Madhyama	Ma	m	Shuddha Madhyama	Ma	M1
7	Teevra Madhyama	Ma	M	Prati Madhyama	Ma	M2
8	Panchama	Pa	P	Panchamam	Pa	P
9	Komal Dhaivata	Dha	d	Shuddha Dhaivatam	Da or Ni	D1
10	Shuddha Dhaivata	Dha	D	Chaturshruti Dhaivatam or Shuddha  Nishadam	Da or Ni	D2 or N1
11	Komal Nishada	Ni	n	Shatshruti  Dhaivatam or Kaisiki Nishadam	Da or Ni	D3 or N2
12	Shuddha Nishada	ni	N	Kakali Nishadam	Ni	N3

Unlike Carnatic system, the Hindustani system has a particular notation system in the Devanagari script (refer to the video for the details regarding it: )

Note that there are three types each of Rishabham, Gandharam, Dhaivatam and Nishadam in the carnatic theory. Also Sa and Pa are considered to be invariant or stable according to both Hindustani and Carnatic systems. 

Reference: Sangeeta Bala Padam (Part-1)