Every year, during the Thyagaraja Aradhana Day, hundreds of singers assemble in Thiruvaiyaru and sing in unison the Panacharatna songs created by the saint composer Thyagaraja (http://thne.ws/dbsinging for one example, if you wish). While their hearts are filled with devotion and emotion, it would be interesting to measure their heartbeats as they sing together. The reason I suggest is thanks to a recent paper that has appeared from Dr Bjorn Vickhoff and a Swedish team of doctors, scientists and musicians in July 9, 2013 issue of the journal Frontiers in Psychology. This paper has aimed to illuminate how singing, and especially choral singing, promotes wellbeing. It shows the connectivity between respiration (breathing rate) and the heartbeat of the singers.

Affects heartbeat, BP

It has been known for some time that breathing affects heartbeat and thus blood pressure. Our ancients had intuitively felt and practised breathing exercises such as pranayama of various kinds. The group led by Dr. T. Pramanik of the Nepal Medical College, Kathmandu tested this concept in 2009 (J.Altern Complement Med, 2009, 15:293-5. doi:10.1089/acm.2008.0440) by asking volunteers to do slow rate pranayama (inhale through both nostrils slowly for about 4 seconds and exhale slowly through both nostrils for a duration of about 6 seconds, no abdominal breathing — bhastrika) and checked their heart rate and blood pressure. When such an exercise was done for 5 minutes, both the systolic and diastolic blood pressure dropped significantly with a slight fall in heart rate. A control group, which did the same exercise, but after taking a parasympathetic drug, displayed no such alteration.

Why does this happen? It is known that respiration rate and variability in heart rate are linked. During inhalation, pulse rate increases and as we exhale it decreases. The vagus nerve, connecting the brain stem and the heart and stomach, gets activated making the heart beat slower. In fact, a group in Valhalla, New York, has come up with a machine (called “Resperate”) which guides you to slow breathing (less than 10 breaths per minute) and thus hopefully treats hypertension.

What has this to do with singing? Another Swedish group (why only Sweden and not India?) showed as early as in 2003 that after a singing session, not only heart rates fell but the serum concentrations of several molecules such as oxytocin increased. While we still do not know what this means, singing seemed to promote more wellbeing and less arousal.

It is against this backdrop that Vickhoff and coauthors discuss their results. They asked volunteers to do three kinds of musical exercises. One group simply chanted a “mantra” (as the Buddhists do in pagodas in Sikkim or Thailand); here the heart rate dropped to an even pace and the blood pressure lowered. As against this, another group was asked to do free humming (not necessarily any guided breathing); here the variation was less regular than in the chanters. And the third group was asked to sing in chorus the song “Fairest Lord Jesus”. We thus have three different levels of respiratory coordination. The results on the choir singers were remarkable. As they sang in unison, their heart rates synchronized as well. In other words, music structure determines the heart rate variability of singers.

Music thus communicates with the autonomous nervous system in two ways — the vagus nerve connection and its action, and audible clue. Singing demands regulated breathing.

Breathing and heart rate are linked through the autonomous nervous system. The vagus nerve from the cranium acts parasympathetically to modulate the heart rate. This allows for synchronising the rate of breathing with heart rate. And in group singing, it leads to synchrony and joint action.

Larger implication

This has a larger philosophical and sociological implication. As the authors guess, such a joint action may lead to joint perspective and joint intention. To quote them: “in other words, singers may change their egocentric perspective of the world into a “we perspective” which causes them to perceive the world from the same point of view (of for example religion, politics or football team) and thus defining who we are….. if collective singing creates joint perspectives, it would be bonding in the deepest sense”. Singing together may thus be good for the heart in a broader and deeper way. In other words, music leads to mood regulation and social bonding. And as Professor David Huron of the School of Music, Ohio State University had wondered why people sing together at all, and whether music is an evolutionary adaptation that has been useful in bringing people together as communities for mutual advantage?

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