Why classical music can make you cry, according to various theories

Most of us would agree that music is a language, arguably humanity’s most expressive and oldest language. What it doesn’t have, unlike speech and writing, is precision.

Music can be used to express, for example, a feeling of love towards someone – as Gustav Mahler did for Alma in his Fifth Symphony’s Adagietto – but not to say ‘where were you till 3am last night?’ (possibly a question he wanted to ask later in their marriage).

Music has its vocabulary and syntax, just like a verbal language. And its complexity is at least equal to Polish, if not Finnish. But the vocabulary and syntax of music is a self-contained world. It can’t be pinned down or translated, like the meaning of ‘apple tree’ or ‘it is raining’.

Or can it? In tone BBC Music article various contributors including me have written about music that reduces them to tears (in a good way). The questions of ‘why?’ and ‘how?’ have intrigued musicians for centuries and, more recently, neurologists and psychologists as well. How our brains process physical signals such as sound waves and convert them into ‘emotions’ is still quite mysterious.

Is it possible, though, to start at the other end of the process: to take passages of music where the effect on the emotions is generally agreed – whether that effect is happiness, nostalgia, sadness, hope or hopelessness – and analyse the musical constituents that apparently cause that to happen?

Music theorists have been fascinated by that for centuries. In the medieval church, certain modes such as the Dorian or the Phrygian were associated with certain moods, and these rules were rigidly enforced. Indeed, one of the boldest things about early Renaissance composers such as Dufay and Josquin was their determination to produce more sophisticated emotional effects by breaking those rules.

Through the centuries, composers became increasingly sophisticated about using harmonic progressions, melodic phrases or even (in Beethoven’s case, for instance) just a rhythmic pattern to convey emotions. So much so that Wagner was able to organise a whole cycle of operas, The Ring, using ‘leitmotivs’ – recurring snippets of melody or harmony – to enrich the drama and guide our ears through it.

The English musicologist Deryck Cooke – best known for completing Mahler’s Tenth Symphony – attempted to broaden this way of understanding music’s emotional power in his book The Language of Music. Published more than 60 years ago, it’s still a fascinating read. Cooke’s theory was that what Wagner invites us to do – identify a network of harmonic or melodic snippets, each with a specific dramatic or emotional function – is something many other composers have done subconsciously.

What’s more, he argues, those composers have often adopted similar melodic or harmonic figures to achieve the similar expressive effects. In other words, they deployed a common language of music, using a stock of what today we might call soundbites with meanings that can be specifically identified. To illustrate his argument, he applies this analysis to two symphonies by composers who lived more than a century apart: Mozart and Vaughan Williams.

Well, the shortcomings of this approach were pointed out by critics at the time and haven’t diminished since. Cooke drew his examples not just exclusively from European art music, but (on the whole) from a narrow historical strand of it. The musical vocabulary he identified would be unlikely to apply to, or explain the expressive potency of, an ancient folk melody from Africa or Asia.

In a way, though, that doesn’t matter. Cooke wasn’t suggesting that every piece of music ever created uses the same pathways to touch us emotionally. Indeed, it is music’s infinite means of expression that makes it the most fascinating of artforms. What he did argue, however, was that if a particular piece is affecting you emotionally it should be possible to identify the musical ingredients that created this effect.

In other words, you can work out why. Whether that makes it any easier to answer the more complicated question of ‘how?’ is debatable. For that task we probably need scientists who understand music inside-out, or musicologists with a PhD-level understanding of the brain. I hope many more such polymaths appear soon. If we can learn more about the way that created sounds impact on our brains, it wouldn’t affect our love of music – but it would open up new possibilities for using music to treat both mental and physical illness.