I am trying to learn to play Carnatic on guitar by transcribing recordings. From lecture demonstrations I have understood that Carnatic ragams are similar to scales in western music but not identical. The notes alone do not make a ragam, associated phrases and gamakas together with the notes make a ragam. Here is an attempt to understand how the ragam Suddha Dhanyasi should be played on Guitar.
Disclaimer: I am not trained in Carnatic music and so, despite my best efforts, there can be errors in all of the stuff below :-). Also, I am not very good at music notation. I am not even sure if Carnatic can be written in this type of notation. Best would be to listen to the audio clips for timing rather than rely on the notation.
The scale-notes of this ragam are the same as the minor pentatonic scale and I have picked G as the tonic note (equivalent to Sa) since it is a reasonable kattai and is also convenient to play three octaves on electric guitars that have limited access to upper frets.
The G-minor pentatonic uses the following notes: G Bb C D F G’ and these correspond to the notes in the Suddha Dhanyasi (SD) ragam:
Arohanam: S G2 M1 P N2 S’
Avarohanam: S’ N2 P M1 G2 S
The image below shows the typical box patterns for two octaves of the G-minor pentatonic scale. Though it is possible to play SD notes this way, the box is not ideal to play carnatic. Carnatic gamakas (micro-tones produced by slides) cannot be played if one were to strictly stick with the box.
SD has to be played as three (or more) notes per string. The notation below shows three octaves of the G-minor pentatonic played three notes per string. Most carnatic songs span at most three octaves.
Those were the scale notes of the ragam. The notation below shows how to play the arohanam and avarohanam of SD with gamakam for two octaves (the third is identical, just a change in strings). In this ragam the swaras G2 and N2 can be played plain or with gamakam. On guitar gamakas are played as slides rather than bends (I believe in Veena both techniques are used).
Gamakam for G2 is played as a slide S-M1-G2 in arohanam ascent and as M1-G2-M1-G2 in avarohanam.
Gamakam for N2 is played as P-S’-N2 in arohanam and as S’-N2-S’-N2 in avarohanam.
Here is an audio sample of SD arohanam and avarohanam played with and without gamakam. Both swaras can be played plain as well. When to play a swara with gamakam seems to be based on context and I think that can be learnt only by playing a lot of songs in the same ragam. From the instrumentals that I have heard, it seems that sliding from one note to another is common and there are no specific rules.