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WHAT kind of music do monkeys like? If this question has ever troubled you, then meet ex-club DJ, obsessive record collector and cognitive scientist Josh McDermott. He has spent 15 months trying to answer it, including testing a barrel of cotton-top tamarins and common marmosets to see whether they prefer a soothing Russian lullaby or snippets of a German electronic techno track called Nobody Gets Out Alive. He has also given the animals a choice between an instrumental lullaby, a sung lullaby, a Mozart concerto and nothing. He has even subjected them to a barrage of dissonant sounds to see how they would react.
Monkeys arenât so different from us, evolutionarily speaking, but if you thought they might have similar tastes in music to humans, you will be surprised at what McDermott, now based at the University of Minnesota in Minneapolis, and his Harvard University colleague Marc Hauser have discovered. Admittedly, you may share the monkeysâ preferences for a fluted lullaby over Nobody Gets Out Alive, with its machine-gun burst of percussion and odd synthetic sounds, but their choice from the wider selection of gentler music is decidedly different. Unlike humans with our diverse preferences, the monkeys chose silence above any sort of music every time. Most baffling of all, though, is the discovery that monkeys do not seem to discriminate between melodious tunes and the sorts of discordant sounds that many people would consider a form of torture.
These experiments, say McDermott and Hauser, show that some of the fundamental motivations that humans bring to music are missing in monkeys (). Commenting on the findings, Isabelle Peretz, a neuropsychologist at the University of Montreal, Canada, suggested that âonly humans have a natural, or innate, inclination to engage with musicâ (). Can that really be the case?
Peretzâs perspective is rooted in a long tradition that sees everything about human music as unique â not just our musical tastes, but also how our music sounds, how we perceive it and how and why we make it. Proponents of this view argue that human musical instrumentation is unrivalled. They say that the extravagant variety of ways in which humans express themselves musically is unmatched in any other species â we use music to sell goods, pray to Gods, motivate ourselves and for pure pleasure, whereas even a virtuoso songbird sings only for sex or to mark out his territory. In this view, the music of other animals, while coincidentally like our own, is in fact nothing more than sound serving a straightforward biological function. McDermottâs findings seem to fit this picture.
Nevertheless, some experts are starting to question the orthodoxy. Indeed, a growing body of evidence suggests that human musicality is not that special, that even species that have evolved musicality independently of primates have rich musical lives, and that we can learn more about the nature and origins of music if we just tune in to them.
Whatâs in a tune?
One of the first pillars of musical wisdom to fall was the idea that humans alone appreciate melody. Most of our music is created from a finite group of notes that span an octave. Whatever the scale, notes are combined and recombined into patterns we call melodies. When we hear music, the pattern of notes in a melody is more important to us than their absolute pitch â we recognise Twinkle, Twinkle, Little Star as the same song whether sung by a child or a man. Music researchers have long suspected that this crucial ability was unique to humans, and a slew of experiments seemed to prove it. Researchers found that if they played a tune to starlings, zebra finches or pigeons, and then transposed it up or down an octave, the birds did not hear the same song. Instead, they seemed to hear two different lists of absolute tones. Likewise, capuchin monkeys who learned to respond to a tune to get food did not recognise their food music if it was transposed by an octave.
In 2001, however, a study by Anthony Wright and colleagues at the University of Texas Medical School at Houston put these findings in doubt. They discovered that rhesus monkeys could transpose tunes by whole octaves without great difficulty â but only when they were tested on childhood songs, such as Happy Birthday, characterised by strong tonal transitions. When Wright tested monkeys with music that had only a weak melody, he found they couldnât even remember the tunes let alone transpose them (). Previous experiments, he points out, had used either atonal music or notes with no melody at all, which could explain the contradictory findings. It seems in this respect at least our musical abilities are not so different from other primates, since we also have difficulty recognising atonal music if it is moved up or down the scale.
Neither are we alone in appreciating the essence of different styles of music. Ava Chase of the Rowland Institute at Harvard in Cambridge, Massachusetts, has shown that carp can tell the difference between baroque music and John Lee Hooker, depressing a button with their snouts to indicate which is which (). Carp do not even use sound to communicate, but they are renowned for their sensitive hearing. Java sparrows can not only distinguish between Bach and Schoenberg, Shigeru Watanabe at Keio University in Tokyo, Japan, found that they could then apply what they had learned about the differences between classical music and the more modern stuff to discriminate between the beautiful melodies of Antonio Vivaldi and the more atonal strains of Elliott Carter. Unlike McDermottâs monkeys, Watanabeâs sparrows also appeared to engage with the music, showing clear preferences for the prettier, more harmonious excerpts and choosing to listen to these rather than sit in silence.
Studies of species that make music, or something beguilingly like it, also put paid to the idea that there is little musical creativity outside our own species. Songbirds, for example, arrange and rearrange specific sets of notes into phrases and larger themes akin to our melodies. Some also vary rhythm, as well as pitch, in the same ways we do.
Humpback whale songs also use some of the same structural principles we employ. They combine phrases lasting about 15 seconds into themes of about 2 minutes. Phrase endings can correspond rhythmically, like rhymes in our lyrics. Several themes then go to make up a song of perhaps 12 minutes in length, which may be sung over and over. The longest recorded whale song cycle lasted for 21 hours.
Seal âmusicâ is the most foreign to human ears, yet their sounds deserve to be called songs, according to Tecumseh Fitch, a expert in bioacoustics at the University of St Andrews in Fife, UK. The complex structured vocalisation of âtrueâ seals and walruses comprise trills, clicks, rasps, grunts and âa remarkable bell-like toneâ, he says.
Birds, whales, seals and humans share not just complex songs, but the ability to learn them â they are not simply hard-wired to produce musical sounds according to a genetic timetable, as many other animals are. This confers an additional creativity. In the same way that human groups have different kinds of musical traditions, different groups of whales have different dialects, and it is possible for one to influence the tastes of another. It has been documented more than once that a whale pod will abandon its own tunes for the new sounds of a strange pod.
All this still leaves the difficult question of what the music is for. Those who argue for the uniqueness of human music say we create it for an endless and unconstrained variety of reasons, whereas animals sing only in a few specific and unwavering contexts. Birdsong is confined to males, and its only purpose is to woo a mate and protect territory. Similarly, whales only sing in breeding grounds at a particular time of year. Moreover, animals never practise by themselves, while humans will sit alone and hum, sing, beat a drum or strum a guitar for hours on end.
The counter argument holds that there is no absolute difference between humans and other animals, it is only a matter of perspective. According to Fitch, constraints on human music are underestimated and those on animal music often overestimated. Sex, bonding and competition may not explain all human music, but they clearly animate a lot of it. Whatâs more, a substantial amount of human music has a narrow application â think wedding marches, funeral dirges, football chants and the like. As for the animal world, whales have been heard to sing outside their breeding grounds, and birds sometimes sing quietly to themselves in a way that looks remarkably like rehearsal in humans. It is not just male songbirds that sing either â in some species, males and females even duet. And while there is no doubt that birdsong is used to signal to mates and rivals, it also has other roles. It can act like a password for a group and play a part in group bonding. âEven within a single species, song functions in multiple ways,â says Fitch.
The pleasure principle
So, what about the charge that humans alone take pleasure from music? Notwithstanding the perverse pleasure we get from listening to melancholy tunes, probably the most important reason we engage with music is that it makes us feel good. Brain scans show that the feeling of euphoria you get when listening to music is accompanied by activity in the same parts of the brain that respond to the rewards of food, sex and psychoactive drugs. Then there is the social aspect. Robin Dunbar at the University of Oxford has studied the way group singing and drumming makes people feel. âMusical activity does seem to produce endorphin surges, which are presumably what give you the âhighâ from engaging in this otherwise rather odd activity,â he says.
Of course you cannot ask an animal how it is feeling, but some researchers argue birds only sing when their hormone levels are high, implying they are little more than winged automata making âbeep boopâ sounds. Fitch, for one, is not convinced. âBirds probably sing because it feels good â fulfilling biological drives typically does,â he says. He draws a parallel between sex and why we do it. âThe ultimate evolutionary reason is to produce offspring, and that is certainly part of the story,â he says. âYet we also do it because it feels good. Thatâs a valid reason! We do it more when our hormone levels are high, and less when theyâre low â thatâs a reason too.â
âIf birds only sing when their hormone levels are high, they are just winged automata making âbeep boopâ soundsâ
The notion that birds might enjoy singing is bolstered by a study published in 2006 by Erich Jarvis and colleagues at the Duke University Medical Center in Durham, North Carolina (). They discovered increased dopamine levels in male songbirds when they sang. The levels were especially high when the birds sang to a female. Dopamine, known as the âfeel-goodâ neurotransmitter, is important for learning. It is not yet clear what role it plays in birdsong, says Jarvis, but he suspects that its primary function is to induce reinforcement learning and that its secondary function may be to create a feeling of euphoria.
Jamming bonobos
Bill Fields at the , agrees that music doesnât just make people feel good. Along with Sue Savage-Rumbaugh and others, he is engaged in an ongoing project to explore the musical tastes and abilities of language-trained bonobos, including the famous Kanzi and a female called Panbanisha. A music session at the Great Ape Trust usually involves a live performance with local musicians, but the animals have also jammed with luminaries including Peter Gabriel and Paul McCartney. The bonobos get a choice of instruments including the xylophone, tambourine, harmonica and maracas, but typically focus on one throughout the session â Panbanisha likes the keyboard, whereas Kanzi prefers the drums (though he enjoys playing the piano in a percussive way). The result is a collaboration, involving an emotional calling back and forth between human and bonobo. Whenever the apes have engaged in a music session, says Fields, âthey look different for days afterwardsâ. The music seems to relax them.
Perhaps the similarities between these enculturated apes and ourselves is not so surprising. After all, bonobos and chimps are our closest living relatives. Chimps may not sing as their primate cousins the , but Fitch believes that the origins of musical instrumentation may be found in their behaviour in the wild, where they regularly drum on naturally resonant objects, such as the buttresses of trees. Some researchers even think that, like whales, chimpanzees groups have distinct cultural practices of drumming and vocalising.
Despite all this, the traditional view about the limited musicality of animals still prevails, and many experts remain convinced that human music is unique. There are signs that things are shifting, though. McDermott, Hauser and Fitch all agree that the components of music probably evolved in different ways at different times â it is mainly the when and where that they disagree on. They also agree that we still have much to discover about the similarities and differences between ourselves and other animals. Fish may be able to tell baroque from the blues, for example, but do they distinguish between these musical styles in similar ways to us and, if so, how is that?
âFish can tell baroque from the blues but do they distinguish between these musical styles in similar ways to us?â
As for McDermottâs monkeys, at least one mystery has been resolved. Given their indifference to music, why do they choose the lullaby over the techno? Suspecting this had more to do with a general response to tempo than any discernment of style, McDermott and Hauser offered them a choice between a soundtrack of 60 clicks a minute and one of 400. Sure enough, the monkeys went for the low-tempo track. In the natural world, the researchers point out, a rapid sequence of sound often occurs in negative situations, such as fights and storms. Then again, it might simply evoke the thump-thump-thump of a wildly racing heart.
Read more about music in our special issue
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