Why is Raag Yaman played in serious devotion or Raag Bhimpalasi full of yearning? Why might one find Raag Malkauns soothing but Raag Marwa foreboding? Does a tune express an emotion that a listener responds to or does it evoke a feeling in its audience? A team from the National Brain Research Centre in Manesar, Haryana, studying the links between music and emotion in Hindustani ragas has found definite links between tone and tempo in eliciting positive or negative emotions in listeners.

Nandini Singh, head of the speech and language laboratory at the centre, was studying how sung speech can be used to communicate with autistic children when she encountered the question of whether they would respond to emotion as expressed through music. In the course of planning the autism response studies she decided to first standardise musical stimuli to gauge emotional response. “We knew the emotions that these ragas were supposed to elicit but on a scientific basis I have to establish that,” Singh said. “I cannot go on anecdotal evidence or say that ‘the Natyashastra says’ or ‘Bhatkande says’.”

Ancient Indian texts document emotions associated with Hindustani classical ragas, each raga being a deliberate combination of notes used to create a particular mood. Musicians play to invoke certain feelings, independent of their own emotions. Singh and her fellow researchers ran an online study with 122 participants to find out what emotions 12 specially composed Hindustani classical pieces brought out in the majority or respondents.

Each respondent logged into the study online where they listened to each raga, composed for the study by Pandit Mukesh Sharma. After a particular piece was over, a respondent would be directed to a list of eight emotions. She had to rate all the emotions she felt during each piece. The researchers designated the response given by the maximum participants as the emotion elicited by a particular raga.

At the end of the study, published in the open access journal Frontiers in Psychology, they found that each raga elicited distinct emotions when played in alaap, which is the slow form of presentation without a rhythmic cycle, and the quick-tempo rhythm-bound gat. “You see that people listening to the alaap will say it is calm and soothing across the spectrum,” Singh elaborated. “When it moves to gat the finer emotions seem to emerge. Most of the people who are participating are untrained people and the tempo helped them give the piece and emotional rating.”

For instance, listeners felt calm and soothed when they heard ragas Hamsadhwani, Desh and Jog in alaap. But when played in gat the same listeners felt reported feeling happy or romantic.

Unexpectedly, the study also showed that major and minor intervals between notes could significantly dictate the mood. The occurrence of the minor second, for instance, signified a transition from positive to negative emotion. None of the ragas elicited anger or krodh in any of the respondents.

The next step, Singh said, is to analyse the effect of Hindustani music on people across cultures, to see in what ways training and cultural affinity affects emotional response. Yet another step forward will be to examine the neuro-circuitry underlying the response to music – whether a single region of the brain modulates emotion or whether different regions of the brain generate positive and negative responses.

Here are four audio pieces from the first analysis.

The soothing Desh in alaap



The plaintive Basant Mukhari in alaap



The happy and romantic Desh in gat



Basant Mukhari filled with longing when played in gat