Have you ever been a little discouraged or depressed – only to hear a familiar song on the radio which somehow lifts your spirits, if only for a few minutes? Have you ever been in the middle of an ordinary day – busy, frustrating, chaotic – and upon passing a boutique or cosmetic shop you hear a song that you’ve not heard for years. You feel a little shiver inside, and the hairs on your arms stand up. You might even go into the shop, if only to hear the whole song.

Just recently, while shopping for Spam in the local Foodland, Joy Division’s “Love Will Tear Us Apart” crackled over store’s speakers. I was so taken aback that I dropped the tin of Spam. For many memories are wrapped up in this Joy Division song, and for ten minutes or so I felt inexplicably moved, as though the song had somehow released the past.

What is it about an arrangement of sound that has such a profound effect on us?

Well, like many things in life (sport, sex, Krispy Kreme doughnuts), it all comes down to chemicals. But while it’s understandable that sex, food, and drugs might trigger release of this pleasure chemical (dopamine), it is less clear why a sequence of sounds might produce the same reaction.

A Canadian study in 2001 used magnetic resonance imaging to study the brain areas activated by music. And in the limbic and paralimbic areas they found the same rush of dopamine, a neurotransmitter involved in pleasurable activities, as with food, sex, and addictive substances. It was a strange discovery because music is abstract, unlike sex or food.

The Canadian study also found that there were two releases of dopamine – responses to both anticipation and fulfillment. There is a rush of excitement simply over what the next sound might be.

Why is music such a powerful drug on its own? It’s possible that our brains just love predicting and decoding patterns. Early theories on emotion suggest that music sets up aural patterns that coax our mind into unconsciously predicting what comes next. If the prediction is correct we receive a little reward – a jolt of dopamine.

However, that doesn’t answer the question about our need for music to survive or propagate the species. Musicologist David Huron suggests that the practice of making mental predictions based on limited information has always been essential to our survival.

On the African plains, he suggests, our ancestors would not have waited to find out if a particular sound was a zebra, an aardvark, or a lion. Bypassing the ‘logical brain’, the mental processing of sound would prompt a rush of adrenalin that prepares us to get out of there, thus contributing to a good outcome. (No one was eaten by the aardvark!!)

Most of us have experienced the sudden swell of emotion when hearing a piece of music – whether Slipknot, Steely Dan or Sibelius – and it feels out of our control. Even though we realise it is ‘just a sound’ and there is nothing essential about the phenomenon, we can’t turn off this reaction, nor can we always predict it.

It seems we both need and enjoy this complex interplay of expectations, predictive logic, and emotions that music provides.

Adding another level of complexity to the musical enjoyment phenomenon is that our reaction to music will contain a cultural aspect. For example, waltz rhythms sound natural to Western Europeans, while Eastern Europeans are more accustomed to rhythms that may sound complicated to those outside their regions. We also have tastes regarding musical complexity, with some people stimulated by minimalism, and others bored by it.

So, what have we learnt? That our response to music is complex and multi-faceted? That there is some mysterious reason that the brain produces ‘pleasure chemicals’ when we anticipate and listen to music? That music is like a medicine – producing a drug that makes us feel good?

While scientists continue to investigate the phenomenon, I’ll forget all the above, slip on some Jimi Hendrix, some Heart, some Hayzi Fantayzee, and enjoy the dopamine….

Thanks to Psychology Today, BBC and Health Guidance.org