We now come to the most decisive characteristic which gives the raga its unique structure, the chalan.
We have seen so far how a set of swara are chosen to form a Raga. To give the Raga its unique melodic theme, these swara need to be rendered in a specific manner. This specific manner is called the chalan of the Raga.
Various factors which collectively go on to specify the chalan are:
1. The sequence in which the swara are taken.
The chosen swara can be connected in various ways. In one straight line, one after the other, or jumping over the next one, coming back and retracing the line in a circular manner. The swara lines which are thus created actually become the basic melodic design, or the theme of the Raga.
2. The manner in which the successive notes will be connected.
Successive swara in a design could be connected with each other in different ways. They could be joined smoothly with a long glide ( known as the meend), or with short straight lines, or then just as discrete points in a staccato manner. This further helps complete the picture of the Raga, which can actually be visualized.
3. The time dwell for each swara.
This picture is drawn on the canvas of time. So we have to look at this element closely, and consider the time given to each swara. At one end, a swara could be just touched upon fleetingly, or then at the other extreme, it could be used as a resting place, with long dwell. The dwell could again be different while going up in the aroha, and while coming down in the awaroha.
4. The Vaadi and the Samvaadi swara, the focal points.
Finally, this picture is provided with two focal points, the vaadi and the samvaadi swara. These two normally are in the opposite parts of the saptak ( If the vaadi is in the poorvanga, then the samvaadi is in the uttaranga, and vice versa). They also have by default a Sa-Pa or a Sa-Ma relationship between them. What this means is, if we make a small design around the Vaadi, we can compliment it with a matching design around the samvaadi. A seasoned musician keeps on exploiting this throughout his development.
The clip below should further help understand the concept.
So finally we have a well defined structure, which has a good amount of objectivity, enough for a musician to have an image. This image is strong enough to be almost the same for all the musicians, and to be propagated from generation to generation, with a good amount of fidelity. Thus, when different musicians present a particular Raga, it is as if they are describing the same person.
Let me say once again, that the Ragas have evolved over centuries. So the melodies came first, the rules followed, just inferred and put down as the common thread across these. So when an artist learns the chalan, he doesn’t go by the rules, but rather follows the Guru, and internalizes it. The long process largely goes by negating and avoiding what is not correct, rather than trying to understand what is right.
I am aware that this topic deserves a lot more explanation. We will definitely come back to this again at a still finer level.