The Raga Network
“What raga is this?”
My Carnatic music teacher gestures to me after singing multiple sets of notes or swaras. The sruthi box humming in the background is comforting in the silence of the room. Every Wednesday and Saturday, I would sit on my teacher’s carpet and sing- not the music traditionally performed in a choir at school- but music that embodied my South Indian culture and tradition that I was trying to preserve in a country halfway across the world.
Carnatic music is a style of music that originated in Southern India thousands of years ago. This style of music spans multiple languages including Tamil, Telugu, Malayalam, Kannada, and Sanskrit. What is unique about Carnatic music is that the tune and rhythm are as important as the extempore and lyrical aspect of the song. However, what is important to note about Carnatic music is also mentioned in the following article (https://www.acharyanet.com/carnatic-ragas/). The most complex aspect of understanding Carnatic music is the structure and how the music scales are organized. As explained in the article, ragas are simplified into scales that contain swaras. These swaras are then structured in the form of a scale going up (called the Arohana) and a scale going down (called the Avarohana). Each of these ragas contain 12 notes in a scale which are divided into 7 types of notes. Using the 16 possible notes coupled with placement rules, a system of 72 parent ragas has been created.
These 72 ragas are then organized into chakras based on the similarities between each raga’s notes. In this application, a raga network would be based on the note changes between each raga. A positive link is determined by there being 0 to 2 note changes between the ragas. Anything greater than that is a negative link. This in turn creates a network where the viewer can understand which ragas are similar to each other and how the resulting raga triangles balance based on this. This is otherwise known as the structural balance theorem. A balanced triangle hints that there is similarity between the ragas chosen, but an unbalanced triangle proves that there are differences in the combination of ragas. Having a network structured like this makes it accessible to beginners who wish to learn about similar ragas based on the predetermined structure of Carnatic music.
In this example, let us look at three different ragas: Kanakangi, Ratnangi, and Senavati. For reference, Kanakangi is Node A, Ratnangi is Node B, and Senavati is Node C. Given the similarities in the notes for Kanakangi and Ratnangi, we can say that they are part of the same chakra; in this case they are both part of the first chakra, Indu. They also only have one note change between the two ragas. Therefore, they have an edge linking the two nodes together, and it is positive. Senavati has different notes compared to both Nodes A and B, but there is only one note change between Nodes A and C and two note changes between Nodes C and B. As a result, there is still a positive link between Node C and B and Node C and A. Given this we can conclude that this triangle of ragas is structurally balanced. In addition, it is determined that the ragas listed are all similar.
Let us look at another example, but this time it will be an unbalanced triangle. Using the ragas Mohanam, Purvikalyani, and Thodi, we can draw another triangle with Node A being Thodi, Node B being Mohanam, and Node C being Purvikalyani. All of these ragas have more than two notes different from each other, so each of the links between the three are negative. This creates an unbalanced network. An unbalanced network means that the ragas all sound different, and there is a lot of variation across the note scales between the ragas.
Work Cited:
“Carnatic Ragas.” Acharyanet, 8 Apr. 2021, https://www.acharyanet.com/carnatic-ragas/.