Raga Darbari Kanada has often been described as the Emperor of Ragas and the Raga of Emperors. These descriptions recall the raga’s association with Miya Tansen at Akbar’s court, and the majesty of the Mughal Empire at its zenith. But, such imagery could not have either surfaced, or survived through the centuries, if it had not also been supported by the melodic character of the raga.
The key to the majestic aloofness of the raga lies in the ponderous deliberateness with which it has to be rendered. This “ponderous deliberateness” of musical expression owes itself primarily to the “andolit” (oscillated) treatment of two swaras – komal Ga, and komal Dh – in the ascent as well as the descent. These two oscillations are fundamental to the sculpting of the two phrases which virtually define the melodic personality of Darbari Kanada – [g M R] and [d n P].
These oscillations around (komal) Ga and Dh swaras define a very specific treatment or intonation of these swaras in Darbari. Some authorities even believe that Darbari does not use the common (komal) Ga and Dh pitch-ratios to base-Sa. Instead, it uses their suppressed micro-swaras (shrutis). According to this view, these suppressed micro-swaras are accessible only as suggestions arising from an oscillation between the natural Re and the flat Ga (for komal Ga) and between Pa and the flat Dh (for komal Dh).
In imparting a sensitivity to these nuances of Darbari Kanada to their disciples, traditionally trained Gurus have often used very obscure language and imagery. The logic of these oscillations is, however, easily understood through acoustic principles -- essentially, the tonal geometry of the two pivotal phrases of the raga: g-M-R and d-n-P.
The first and last swaras in these phrases, Re-Pa and Ma-Ni, are in perfect first-fourth correspondence with a ratio of 1.333 between them. But, the linking swaras, (komal) Ga and (komal) Dh are only in near-perfect correspondence with a ratio of 1.367 between them.
To achieve a symmetry between the lower and upper halves of the Darbari Kanada scale, the two pivotal phrases need to be in perfect phraseological congruence. This is not possible until (komal) Ga and (komal) Dh are brought into perfect acoustic correspondence with each other.
The oscillated treatment of (komal) Ga and Dh explores the relevant microtonal regions for the possibility of tonal correspondence and phraseological congruence. The melodic soul of the raga expresses itself in these explorations.
The aesthetic demands of this tonal geometry might explain why great musicians often favour slow tempo renditions in this raga, and avoid the flattening out of the prescribed oscillations in ultra high-density melodic execution.