Chimpanzee lead guitarists are thin on the ground. The stage at London’s Royal Albert Hall sees few lemur violin virtuosos. Conventional wisdom has it that music is a relatively modern human invention, and one that, while fun and rewarding, is a luxury rather than a basic necessity of life.

This appears to be borne out by the archaeological evidence. While the first hand axes and spears date back about 1.7 million years and 500,000 years respectively, the earliest known musical instruments are just 40,000 years old.

But dig a little deeper and the story becomes more interesting. While musical instruments appear to be a relatively recent innovation, music itself is almost certainly significantly older. Research suggests it may have allowed our distant ancestors to communicate before the invention of language, been linked to the establishment of monogamy and helped provide the social glue needed for the emergence of the first large early and pre-human societies. There is also emerging evidence that music might have even deeper origins: some monkeys can distinguish between sound patterns in ways similar to how humans can recognise slight differences between melodies.

There is a clear musical tradition

A literal reading of the prehistory of music begins about 40,000 years ago, with Europe on the brink of a momentous change. The region was then home to the Neanderthals, who had inherited it from earlier human species stretching back a million years. But now a new species of human - our own - was racing across Europe. Homo sapiens were clever in a way that Neanderthals were not. Perhaps most importantly, they were armed with much more effective weapons. Within about 5,000 years our species had spread and multiplied so effectively that it may have outnumbered the Neanderthals 10 to one. Not long afterwards the Neanderthals vanished entirely.

The dramatic pace of this change suggests there were some fundamental differences between our species and the Neanderthals. The evidence on (and in) the ground strengthens the case. For instance, the Neanderthals sometimes lived in caves but for the most part didn’t bother to decorate them, although evidence published in September 2014 suggests they may have created some rudimentary, abstract art, etched into a wall of a cave in Gibraltar (see video below: credit: S. Finlayson, Gibraltar Museum).

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However when our species arrived cave walls became canvases for impressively ambitious paintings. Modern humans also began carving human figurines and animals out of bone and ivory shortly after they arrived in Europe. And, to go with their new fascination with the visual arts, they began making bone and ivory musical instruments.

“There is a clear musical tradition,” says Nicholas Conard at the University of Tübingen in Germany, who helped discover many of the best examples of these early instruments. “In southwest Germany we have eight flutes from three different sites.”

These artistic endeavours might at first glance seem irrelevant to our species’ remarkable success at the Neanderthals’ expense. Indeed, some researchers have argued that music is little more than a useless byproduct of our intellectual advancement. For Conard and others however, music and art were important in helping those early modern humans forge a sense of group identity and mutual trust that enabled them to become so successful.

“I’d say the symbolic artefacts we find show that there were more people on the ground and this was social glue that helped hold people together and contributed to their adaptive advantage,” he says.

Our poor Neanderthal cousins may have struggled to build that level of social unity and failed to compete partly because they lacked art and music.

There is growing evidence that Neanderthal cognitive capacities were comparable to those of modern humans

In truth, Conard and others think the story is probably more complicated than that because, they argue, the art and musical instruments that appeared in Europe 40,000 years ago are so sophisticated that they must have evolved out of earlier artistic traditions. In 2011, for example, archaeologists revealed they had found tools and shells probably used to mix up body paint 100,000 years ago in a cave in South Africa.

It’s also likely that Neanderthals were not the uncultured brutes of popular imagination. A reassessment of the available evidence carried out by a Dutch group suggests it does not support widely held ideas about the species having only primitive tools and weapons, lacking the ability to communicate using signs and symbols, having a narrow diet and only basic forms of social organisation.

“There is growing evidence that Neanderthal cognitive capacities were comparable to those of modern humans,” says Ruth Biasco at the Gibraltar Museum. It’s not inconceivable that Neanderthals might have made and used musical instruments, she says - although until solid evidence is found to back up the suggestion, she prefers to remain cautious.

In fact, there is at least one candidate Neanderthal musical instrument - a 43,000-year-old bone flute found at a Neanderthal site in Slovenia. The find is controversial, though, with many researchers arguing that the flute’s “finger holes” are nothing more than puncture wounds left when a large carnivore chewed on the bone.

It’s a debate that highlights some of the difficulties in identifying early musical instruments. For one thing, they may not have been made entirely from scratch but from materials that, through natural processes, were suitable for making music. Even today, for example, didgeridoo craftsmen begin making their instruments by searching for trees that have been hollowed out by termites. Recognising instruments like this at ancient human sites is not impossible, says origin-of-music researcher Francesco d’Errico at the University of Bordeaux in France. “But it requires a lot of effort and dedicated research.”

When the vocal anatomy looked like ours you can conclude that they had vocal abilities rather like ours

Iain Morley at the University of Oxford, UK, who has studied the music created by modern hunter-gather groups, identifies another obstacle to finding the earliest musical instruments. In his book The Prehistory of Music, published last year, he emphasised the point that many traditional instruments are made from perishable materials that rot away relatively quickly. This means it may be very difficult to find the earliest objects used for making music, let alone establish whether Neanderthals made use of them.

But in a sense this doesn’t really matter. There is one musical instrument researchers can say with some confidence substantially predates 40,000 years - and it’s one that Neanderthals almost certainly had at their disposal. The human voice may have gained its full vocal range at least 530,000 years ago, suggesting several species of extinct human - including Neanderthals - had the potential to sing.

We know this because of some remarkable fossil finds made within the last decade or so. There is a tiny horseshoe-shaped bone in our neck called the hyoid, and some researchers think its shape changed when our voice box moved down our throat to take up a position that allows us to talk and sing. Archaeologists have now found a small number of these fragile hyoids belonging to Neanderthals and to another, earlier human species called Homo heidelbergensis: they have the same shape as the modern human hyoid.

“I take the view that when the vocal anatomy looked like ours you can conclude that they had vocal abilities rather like ours, as long as they could control it,” says Morley.

The voice box may actually have begun to descend even earlier. Its soft tissue doesn’t preserve in human fossils, but its lower position in our necks affects the shape of the base of our skulls. A careful look at ancient skulls suggests even those belonging to our 1.8-million-year-old forerunners had slightly descended voice boxes. This means our ancestors may have had some crude ability to sing for a very long time, and that the ability gradually improved through time. If so, this would imply that humans had something to gain from using the pitch and tone of their voice - but what?

Charles Darwin, the 19th century naturalist and father of evolutionary biology, was one of the first to try to explain why humans became musical. In his 1871 book on evolutionary theory The Descent of Man, and Selection in Relation to Sex, he proposed it was analogous to bird song, in that it helped males attract mates and warn off rivals. The idea has now largely fallen out of fashion, though, because singing is not an exclusively male pastime: in almost three-quarters of songbirds, for instance, females sing too.

More recently Thomas Geissmann at the University of Zurich, Switzerland, came up with another interesting theory. In a book published in the year 2000, he pointed out that the four other singing primates (some lemurs, tarsiers, titi monkeys and gibbons) all form monogamous breeding pairs - as do many humans, and amongst birds duetting mainly occurs in monogamous species. Perhaps, Geissmann suggested, singing is somehow related to the evolution of monogamy - although exactly how or why is still unclear.

Other explanations for the origin of music emphasise the obvious similarities between human song and language. Most of us recognise that music can communicate to us - even a wordless melody can make us feel happy or sad. Dean Falk at Florida State University in Tallahassee, US, points out that we can also often understand the emotional state of someone from the tone of their voice, even if they are speaking a language we are unfamiliar with.

Perhaps music and language both evolved out of the need for early humans to communicate their emotional state to other members of the group. Other primates often rely on grooming to connect emotionally with their peers - but at some point in our prehistory, humans began to come together in larger groups, and needed a way to broadcast their emotional state to a greater number of individuals to keep the group united.

The case for mothers and infants jump-starting the evolution of motherese, which eventually evolved into proto-language and proto-music, is supported by strong evidence

In the 1990s Leslie Aiello and Robin Dunbar, both then at University College London, suggested our ancestors began communicating with emotional tones they called ‘vocal grooming’ to cement social ties on a large scale. Aiello and Dunbar were really looking for a way to explain the evolution of language, but others including Morley think their emphasis on the early importance of tone shows that the use of emotional tones to strengthen social cohesion might equally explain the origin of music.

Falk thinks a better way to look for the origins of music might be to explore how our anatomy differs from that of our primate relatives. One of the biggest differences is that human babies are born in a far less developed and more helpless state than many other primates. There are obvious reasons why this is the case: even as infants we have large brains that can make childbirth a painful experience for the mother. If our skulls grew any larger in the womb, it would become almost inevitably lethal.

One consequence of our helplessness as newborns is that human babies can’t cling to their mothers for protection and reassurance in the same way that baby chimps can. Human mothers have to carry their babies, which interferes with their ability to perform daily tasks. Falk thinks that mothers in prehistory had to put their babies down at regular intervals to free up their hands for other activities, and that they used an early form of baby talk, or ‘motherese’, to keep them reassured.

I want to investigate to what extent their natural drumming resembles ours, and see what kind of musical patterns chimpanzees can imitate

It might be no coincidence that our ancestors’ brains became particularly large, and their babies perhaps especially helpless, around 1.8 million years ago. This is the same time that researchers who have examined ancient skulls say the human voice box first began to descend in a way that would have made the voice more versatile. “I think the case for mothers and infants jump-starting the evolution of motherese, which eventually evolved into proto-language and proto-music, is supported by varied and strong evidence,” says Falk.

Any, or all, of these hypotheses for the origin of music might be true. There are differences between them, but they all suggest our ability to make and appreciate music was an important step in early human evolution. Many also highlight music’s role in social bonding – fitting neatly with the idea that the 40,000-year-old musical instruments are evidence of the strong social ties that contributed to modern human success in Europe.

But there is still some way to go before scientists have a comprehensive picture of the origins of music. For instance, some primates that don’t use music nonetheless seem to have an ear for a tune. Last year Andrea Ravignani at the University of Vienna in Austria and the University of Edinburgh in the UK found that squirrel monkeys can recognise subtle differences in sound patterns in much the same way that humans can distinguish between different melodies or different word phrases in spoken language.

Why would the monkeys have this ability when they don’t seem to use it in the wild? “I don’t have an easy answer for that,” says Ravignani. He is now studying the musical talents of other primates, beginning by giving captive chimps access to a custom-built electronic drum machine. “I want to investigate to what extent their natural drumming resembles ours, and see what kind of musical patterns chimpanzees can imitate.”

“Abilities that underlie some of our musical traits seem to be showing up in animals more and more,” says Morley. Perhaps that’s because the brain circuits we now use to process music originally had some other purpose. If that turns out to be the case, those researchers ignoring Stone Age flutes in favour of listening to the primal tattoos drummed out by chimpanzees might be in with a better chance of finding the true origins of music.