Music and rhythm find their way into the secret places of the soul, they say! Has anyone ever thought of, how? How does a permutation of seven swaras make its way to the heart? Music is the art of sound in time, organized to the principles of pitch, rhythm, and harmony. An important function of music is its capacity to communicate emotions, as noted by Indian Classical Singer Kishoritai Amonkar, a view that has been agreed upon by almost all music performers till date, also music listeners!
While, almost all known forms of music have been recognized for their effective emotional qualities, the exact causal mechanisms by which musical sounds generate emotions are still unclear. Current models posit that specific acoustic factors embedded in a music signal exploit the physical environment, the cognitive and perceptual processing systems, and the structure of the auditory system, to generate emotional responses.
Further, though the link between music and emotion has been empirically established, most findings lack generality across multi-cultural representations of music. Consequently, while music and emotion studies have standardized the use of Indian Classical music as a staple source of stimuli, only a handful have incorporated genres of music native to other cultures.
Hindustani music, is an ancient musical form of India that emerged from a cultural synthesis of the Vedic chant tradition and traditional Persian music. The central notion in this system of music are ragas, which are described as musical compositions capable of inducing specific moods or emotions. Also, past studies have investigated ragas to have shown that distinct ragas elicit distinct emotions.
A study published recently exploited a novel feature of raga stimuli, namely that of different presentation modes, differing in tempo-rhythm but matched in tonal structure, to study music and emotion. They found that when the same raga was presented in distinct presentation modes, participants reported elicited emotions with varying levels of arousal. (https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0001679)
In sum, Hindustani ragas are robust stimuli capable of eliciting distinct, predictable emotions, with tonal relationships and rhythmic tempo influencing the valence and strength of emotional effects in the listener. It is important to note that the usage of ragas in various music cognition literature is nearly always in the context of cross-cultural differences.
I hope readers come away from this view with an understanding that ragas can be thought of as more than 'world music', and useful for more than only cross-cultural studies of music cognition and emotion.