“After silence, that which comes nearest to expressing the inexpressible is music.” — Aldous Huxley

Music is the sound of everything. Birds do it, bees do it; even elephants and whales sing songs. Music is older than speech; it is the language of the womb and the nursery, the melodies and rhythms that pass between mother and child.

Music is the air given form. And it is no Zen paradox to say that without someone there to hear it, music does not exist. Unless vibrating air molecules find an echo on the eardrum and are reorganised in the cerebellum, is music really there at all?

But when it is there and you are, too, music has an undeniable effect on mood and behaviour. Think of soldiers marching into battle to the sound of drums and fifes; or demonstrators striding along, arms linked, a defiant hymn on their lips. Or picture a pop audience swaying to a sentimental rock ballad holding Bic lighters aloft. With words or without, a song speaks directly to the emotions.

An old song can transport us instantly back to the emotions of an earlier time when we first heard it. When David Bowie, in his song Starman, emulates the soaring octave jump that begins Somewhere Over the Rainbow, is he suggesting the celestial origins of his hero or just hitching a ride on a familiar melody, with all its poignant, nostalgic associations? Music is memory. And the memory of emotions.

Music is the key

“How strange the change from major to minor.” — Cole Porter

The most noticeable emotional effect of music and perhaps the easiest to recognise is harmonic: the distinct mood shift between major and minor keys. By the age of six or seven, scientists believe, Western children learn to associate minor harmonies with sadness. Major keys are more common and hence less emotionally specific, though a brisk tempo, rising intonation and high notes will certainly impart a feeling of exhilaration.

Even without Benny Hill’s hectic visuals, his theme tune (Boots Randolph’s 1963 hit Yakety Sax) would make most of us smile. Compare that bright, manic major-key sound with the solemn, even mournful tones of Beethoven’s Sonata No. 14 in C# minor, better known as the Moonlight. If that contrast seems cartoonish — if you think I’m comparing apples with oranges — consider the triumphant major melody of Ludwig Van’s Ode to Joy, the majestic final movement of his Ninth Symphony.

But this isn’t the whole story; the workings of harmony can be complex. One Sunday morning in a park in Memphis, Tennessee, as an onlooker to a Mother’s Day gospel meeting, I saw a woman first rattle all over her body then faint from the effect of the hypnotic, repetitive rhythms of an unmistakably major-key gospel number. Whether it was ecstasy or exhaustion, I couldn’t be sure.

In Bali, on the other hand, I’ve observed the measured serenity of a gamelan orchestra, its gongs and flutes marching steadily forward in what to Western ears is a distinctly minor tonality — yet the effect is joyous, reflective and not in the least mournful. (In most Asian cultures, from India to Japan, music consists of rhythm and melody with little or no harmony.)

Songwriter Cole Porter was a dab hand at juggling major and minor moods to achieve an emotional effect — in Love for Sale, I Love Paris and What is This Thing Called Love?, to name a few — and in the song quoted above, Ev’ry Time We Say Goodbye, he famously echoes the lyric with an actual harmonic shift “from major to minor”. The effect is almost heartbreaking.

More than one commentator has suggested Porter, a midwestern Protestant, was consciously emulating “Jewish music” as a way to challenge the popular success of the likes of Irving Berlin and the Gershwin brothers. But I like to think he, no less than George Gershwin, implicitly understood that it’s the ambiguity between the minor (flattened) third and major third of the scale — the mi of do-re-mi — that puts the blues in jazz.