From our very first step, humans have been slaves to the rhythm

I’m sitting in my kitchen in Liverpool playing with my favourite app, Radio Garden, and it is a thing of beauty. When you open it, you see a globe spinning through space, like on Google Earth. You turn the globe with your finger to any continent you like, zoom in by pinching the screen until a country or a city takes your fancy, and tune into one of 30,000 radio stations.

There’s nothing like music to transport you, instantly, to a faraway culture. Radio Garden’s sonic tourism is a fix for travel-hungry people marooned by Covid-19. But something deeper is going on because, to take the long historical view – as well as the view from space – our ability to encircle the planet through music brings that evolutionary story to its climax.

Music’s journey to world domination began literally with the first step; when humans’ oldest known ancestor, Ardi the australopithecine, got up on her hind legs 4.4 million years ago and walked. Why? Because bipedalism, walking upright on two feet, forged vital neuronal links between brain, body, and sound, and stamped hominin music with its characteristic walking rhythms. It forever associated music with motion and travel. This is why human music ‘dances’ and ‘walks’, and why it feels so natural that music today soundtracks our lives via our iPhones and earbuds as we saunter or jog through cities.

The journey from australopithecines to soundtracks is traced in my new book The Musical Human. Pooling together evidence from archaeology, anthropology, biology, and the psychology of hearing, I make the case that music drove human evolution: that music was the most important thing we ever did.

After Ardi and her more famous descendant Lucy (3.2 million years BC) starting walking, 1.5 million years ago rhythmic patterns helped Homo ergaster knap flint tools; rhythm coordinated communal labour. Some 500,000 years ago, Boxgrove in Sussex was the site of celebratory ritual dances, as music brought Homo heidelbergensis together into a community. Then, 250,000 years ago, Neanderthals perfected a sing-songy, musical kind of communication. And 40,000 years ago sapiens crafted the first musical instrument out of vulture bones as part of humans’ cognitive revolution.

The skill to make bone flutes coincided with sapiens’ ability to paint figural representations on cave walls, carve figurines, such as the famous Lion-man sculpture discovered in the Hohlenstein-Stadel Cave in Germany, and, presumably, the acquisition of language and conceptual reason. Yet at every stage of human evolution, music was there before language or reason.

Does that mean that music stopped evolving once sapiens achieved behavioural maturity at 40,000 years BC? No, because what happened next lifted music’s journey to a more abstract level. By detaching notes from the human voice, musical instruments allowed us to imagine music itself as a kind of motion, with one note ‘walking’ to another. We love to talk of music in terms of motion through space, but it is really just a metaphor because there is nothing to see except vibrating air.

Listening to music plugs us into the entire animal kingdom, because music is an umbilical cord back to Mother Nature

So why do we do it? There is a neurological basis for why sounds in general evoke movement. Our sense of hearing is closely linked to our vestibular system, which is responsible for keeping our balance when we are walking. Listening to music activates the premotor cortex, basal ganglia and cerebellum, motor areas associated with movement. Indeed, people need only to imagine music – not necessarily to actually hear it – for these brain regions to be activated.

Amazingly, it all goes back to fish. If you uncoiled the organ of Corti in the human cochlea, it would resemble the fish’s lateral line, through which it detects the swimming movements of other fish. Fish don’t hear very well. But they are excellent at detecting motion through water. The biological link between hearing and motion was forged in the sea.

Listening to music plugs us into the entire animal kingdom, because music is an umbilical cord back to Mother Nature. Not only is sapiens a singing ape, our music even resonates with that of insects. Scientists reconstructed the exact pitch produced by the wings of a fossilised bush-cricket, or katydid, from the Jurassic period 165 million years ago. Like its modern descendants, the prehistoric katydid would have chirped in a regular beat, a faculty shared by cicadas and frogs, but also analogous, in the visual field, to the pulses of fireflies and the synchronised waving of fiddler crabs.

Perceiving and synchronising to a regular beat is a foundational musical skill for humans. And that, ultimately, is why we dance. And we sing because music is the food of love, something the humble mosquito understands. Consider mosquito courtship duets. The male mosquito buzzes to attract his mate with a wingbeat frequency of 600 Hz, or D natural. Female mosquitoes hum normally at a pitch of 400 Hz, G natural. Yet just before sex, both mosquitoes modulate their flight tones so as to harmonise at the same pitch frequency of 1,200 Hz, an ecstatic octave above the male’s D. Everything we sing is just a footnote to that.

So what did sapiens bring to the table? On dry land, what hominins and humans added to the mix was the rhythm of walking on two feet. Of course, flutes, like all small instruments, are easily portable, so music started moving in a literal sense too.

The global history of music is really a story of musical travels. The vaunted Silk Road was a musical super-highway for melodies, scales and modes, instruments and performance techniques. Caravans laden with silk, cotton, gunpowder and spice might also have carried lutes. And lutes changed their names everywhere they went: pandoura (ancient Greece), veena and then sitar (India), pipa (China), pip’a (Korea), biwa (Japan), barbat (Persia), oud (Middle East), and the modern guitar.

Paul McCartney’s first guitar, a Zenith, was shipped from Germany. And when Silk Roads took to the sea, ‘Cunard Yanks’, the waiters and catering staff on the Cunard shipping line between Liverpool and New York, carried home rock‘n’roll, rhythm and blues, country and western and the music of Motown and the girl groups to a very receptive John Lennon. The rest, as they say, is history.

The Musical Human: A History of Life on Earthby Michael Spitzer is out now (Bloomsbury, £30)