The Biology of Music: Why we like what we like


As a rule, humans are very picky about their music. I don't mean stylistic choices. Whether you like country, western, or both is up to you. I'm talking about something more basic than that.

A tone is a sound, like a note before it gets a specific name, and a scale is a collection of tones grouped in ascending or descending order. We are able to hear a huge number of tones and, theoretically, there's billions of ways to group them, but humans tend to focus on a very small number of scales, usually made up of either five or seven tones. The same scales are used over and over, throughout most of Western music and much of human music as a whole, said Dale Purves, Ph.D., professor of neurobiology at Duke University and director of the Duke-NUS Neuroscience Program in Singapore. In fact, even styles of music that sound completely different--say classical Chinese music vs. Western folk music--use the same scale, he said. They just use it differently.

So why are we so drawn to certain tones and certain groups of tones? Purves' team thinks they have an answer--an explanation that links what humans like with who they are, biologically.

The key, Purves said, lies in our evolutionary history.

"Any perceptual quality you have is there for some biological reason. They evolved because they provide useful information to us," he said. "So if you take a microphone out in nature and ask what the tonal sounds are in our environmental niche that we would have evolved to appreciate, the tonal sounds you record are nearly all animal vocalizations. And the ones that count the most are the vocalizations of other humans."

The sounds humans make matter most, he said, because that's where we get information about our competitors and our potential mates--the things we need to know to be successful creatures. We developed an ear for the tones common in human vocalizations, the same way a sommelier might develop a taste for fine wines. Those are the tones we find most appealing and thus, the ones we made into our musical art.

The basics of this idea are nothing new. It is, after all, pretty obvious that there's a connection between human voices and human music. But, when people have looked for links between musical scales and the natural changes in the pitch and rhythm of speech, they haven't been able to turn up any solid evidence of a causal relationship. Purves, along with Kamraan Gill, Ph.D., approached this in a different way, looking instead at similarities between scales and the spectrum of--or frequencies in--speech. Here, they hit paydirt. In fact, Purves and Gill found that you can correctly predict which scales are the most popular by how similar they are to the spectrum of human vocalizations. A great example of how this plays out: Rock 'n Roll

"Rock is especially popular because it emphasizes the musical intervals whose frequency relationships are those we hear in the human speech ," Purves said. "That's one of the reasons people like it so much."

Read Dr. Purves and Dr. Gill's paper at the journal PLoS ONE.

Image courtesy Flickr user shankar, shiv, via CC.


  1. My folk music teacher claimed that all human scales are based on some way on the harmonic series, except for some Javanese music, in which the scale was defined by the weight ratio of the gongs, instead of frequence ratio. A bit like the story of Pythagoras’ hammers, in other words.

  2. I’m not convinced. Why does rock and roll need to have bass guitar to sound good? Is there anyone who talks like that? So far the argument seems weak.

    1. It doesn’t need bass guitar to sound good. Stairway to Heaven, probably the most popular rock and roll song, doesn’t have a bass guitar track for most of the song. Also, the article is talking about the intervals of music, not the frequencies. The bass uses the same intervals as the guitar.

      1. The bass is the base, that’s basic:

        What the hell does that have to do with rock’n’roll, anyhow?

        1. …and the bass, she is a beautiful solo instrument too, eh?
          ‘specially the electric bass, if the axesman be fine enough:

    2. thats so true when i lisyen to rock theres not one time i dont liten to a bass guitar i just wonder how it would be with out a guitar… nd i love the gutiar

  3. This is kind of interesting, and I can only concur with anecdotal information. One day some friends of mine and I had smoked some heavy doobies, and we had stayed up pretty late. The birds had started to sing their morning songs, and we all started to realize that the bird’s calls sounded like some kind of post-rock or electronic music. We were so high we thought the birds were singing Kraftwerk.

  4. The reasoning is kind of circular, isn’t it? Human hearing specializes in human voices… but we can also say the opposite: Human voice focuses on those sound best heared by humans…

  5. When I was just a teenager, someone told me that BPM were a function of heartrate, so that anything less than 70 BPM was calming, around 70 BPM was interesting, and more than 100 BPM or so was high-energy dance music precisely *because* your heart would attempt to catch up with it.

    This made a lot of sense to me, and this article is in the same vein. I’m not sure if I agree completely, but it’s definitely an intriguing line of study!

  6. I’ve downloaded the paper, but haven’t read it yet but the title caused me to pause… Just last night, CBC Radio One played a documentary on the late, great Frank Zappa. At the beginning of the documentary, there was a discussion of how the Western eight-note scale wasn’t universal, thus couldn’t be rooted in biology. (The appreciation, or more properly the ability to appreciate music might be rooted in our DNA, but not the particular scale.)

    Off to read…

  7. This is about eleventy-seven kinds of wrong, and I would give a music student a failing grade for submitting this in one of my classes (which is probably why it’s not published in a music journal or a neuroscience journal). Yes, music and the brain is an interesting subject but that doesn’t mean that anyone with a PhD who decides to spout off about it necessarily has anything meaningful to say about it.

    First, they used a subset of 240-tone equal temperament to embed all their candidate scales, based on an egregious misunderstanding of human pitch discrimination ability. Their historical understanding of the evolution of scales is more naive than I would expect from a freshman music student. And in the end all they come up with is that our 5- and 7-note scales contain good approximations to intervals from the harmonic series… Zarlino, in 1558, already knew that.

    There are flaws in just about every sentence of this article and it would be tedious for me to write any more about it here so I won’t.

  8. speedreader, I take it you’ve heard Morgenspaziergang, then. ;) It’s like a walk though a digital forest.

  9. Agree w PaulR #2 & Jon_anon #3..

    Just considering classical Indian music (100+ scales and counting) alone is enough to discredit the article.

    It is probable that harmony, consonance, dissonance, etc is biological. Good data would be nice.

    Last… I don’t think one can make blanket statements of any kind about “rock music” — what sort? Beatles? Metal? Ricky Nelson? It’s all radically different.

    1. Beatles? Metal? Ricky Nelson? It’s all radically different.

      Not so radically different. The Beatles are indistinguishable from Ricky Nelson, when compared with the musical preferences of, say, corals, bacteria, or igneous rock formations.

    2. I’m too am skeptical (at best) about this paper, for the reasons previously stated.

      There’s certainly plenty of opportunity for neuorology folks to get involved in helping us understand how we respond to, and create, music. But to be a workable theory at that level, it needs to cover the full range — and this doesn’t seem to come close.

      And that’s before you start bringing in things like musique concrete and free jazz and some of the less scale-based electronic stuff.

      On the other hand: There *is* pretty good evidence that “music is the enjoyment we take in counting without realizing that we’re counting.” Wolves reportedly tend to like the same intervals we do, presumably for the same reason — they’re the ones which produce interesting beat tones.

      (And I’m a firm believer that art in general, including music, is the enjoyment we take in having our expectations built up and then resolved in an unexpected way.)

  10. Perhaps the Devil’s Chord has interesting neurological underpinnings?

    “The tritone is a musical interval that spans three whole tones. The tritone, sometimes known as the Diabolus in Musica …. The name diabolus in musica (“the Devil in music”) has been applied to the interval from at least the early 18th century.”

    See also — or rather, “hear also” — Sound of fingernails scraping chalkboard.

  11. Bullshit. You ‘like’ what you hear enough. Just like brain worms – those songs that go on over and over in your head no matter how terrible. Pop songs become hits because they get airplay. White kids listen to rap/hip hop because their friends listen to it. The music industry works you to make a profit.

    PS: to get an ear worm out, start singing La Cucaracha – works every time and does not leave you with La Cucaracha swimming in your head.

  12. I have to chime in to agree with the naysayers. As an ethnomusicologist, one of my greatest annoyances is the work done by scientists with insufficient grounding in human musical experience.
    A large body of literature on the many unexpected ways that music differs from culture to culture, and knowing some of this would help these researches develop better experiments. It should be obvious that if you are looking for a biological basis you need to go beyond the confines of Western Art Music and 20th century popular music.

  13. Iannis Xenakis would have something to say about this, and it would probably be rude and pretentious, oh right he’s dead. Maybe there is something to this though ( I kind of doubt it) and it could explain why microtonal music isn’t taking off as much as I would like but when I hear a synth line weaving in an out of just a few Hz (ok maybe several since I doubt I can recognize the difference between 3 Hz. apparently humans can but I think that is usually tested in a lab setting which is much different)it really gets to me emotionally. I personally love compositions based on minimal frequency changes that lie between the semi tones we use in the majority of music.

  14. Music is more than tones. It’s culture. It’s rhythm. It’s multiple textures from gritty to smooth (Have Tom Waits and whatever auto-tuned popster sing the same song…). It’s notions of refinement and rawness. It’s groupthink and individuality. It’s novelty and comfort. It’s sex and anger and patriotism and religion. (Suddenly this sounds like a Scientology ad, so I’ll stop.)

  15. And then there’s the theory that all people are attracted to the sound of rhythmic drumming, because the beating of a mother’s heart drive our growth to birth…

    1. And then there’s the theory that all people are attracted to the sound of rhythmic drumming, because the beating of a mother’s heart drive our growth to birth…

      I once participated in a shamanic drumming exercise: lay on the floor (wrapped in blankets, because metabolism drops), visualize traveling to the underworld while listening to shamanic drumming.

      The drumming is a certain beat frequency: I’m told that the same frequency is used by shamans of different cultures all over the world.

      Other participants reported more or less nothing. But me … I had a hallucinatory experience whose nature and intensity rivaled — nay, outstripped — any acid trip I ever took (back in my acid-taking days).

      Whoo-EEEEEEEEEE — !! We’re talking in-FUCKING-credible mind altering event here. The energy of it kept me dancing and yammering for hours after the event. (Yammering because this “workshop” really provided no cultural context for channeling the voices of the gods. I’m certain that, under more meaningful circumstances, I would have prognosticated the future, diagnosed illnesses, and done the other deeds that shamans traditionally do.)

      Although I was unable to render service to my tribe (not having a tribe), I did, at least, meet my spirit animal guides (dancing frogs) who gave me the clearest possible answer to the question I brought before them.

      Nothing like it in my experience, before or since.

      See Shaman’s Drum @ Wikipedia.

  16. I generally dislike papers that do what this one does –

    Step one: take a nice fresh look at some basic data, mathematically rigorous, and draw some low-level conclusions in keeping with lots of other research out there. This merits a paper at a music-cognition conference or journal.

    Step two: in the discussion section, bring in brand-new biological and historical concepts not seen anywhere in the actual work. I think this goes beyong putting the results into context – the author is synthesizing many disparate areas of study here, with only tentative relationships to his data-set.

    This is a great thought-piece, occasioned by some data. This is not science. Interesting reading, though, and it doesn’t have the broad sweeping scope that the boingboing blogger and some commenters seem to think it does.

  17. I’m going to go out on a limb and suggest three simpler explanations:

    First, we like what we like because it’s what we’re used to and we’re not as likely to listen to things that are too different.
    Second, most music uses the same scales because most instruments are designed to play those scales and make it harder to play using a new scale.
    Third, most people learning to play instruments are taught those scales and would have to teach themselves to play in a new scale.

    When you put them together, you get a system of music that reinforces itself. To have new scales enter popular music, you would have to have musicians who want to experiment with new scales, instruments that can play the new scales easily and audiences who are interested in the new result. It can happen, but it’s not common.

  18. The fact that commonly used musical scales have a strong relationship to the harmonic series is not at all new or surprising. That would be a *physical* rationale for musical scales. As the previous commenter observed, the discussion section introduces a biological rational that is not backed by in any research. Work by Parncutt and Terhardt seems to disagree.

    Looking at scales as a potential collection of harmonic intervals is a distinctly Western perspective, and eliminating any kind of nuanced tuning from the analysis also flattens the cultural perspective. With that in mind, it does not surprise me that all five and seven note scales start to look alike. And, other scales are discarded because they are “not recognized as formally… in Western music theory.”

    Interesting article, nonetheless, for the ideas it brings up.

  19. This is one of those instances when the comments are more fun (and useful) than the article. (Possibly because there was no way for even the most dedicated loon to bring politics into it.) As a Humanities teacher, I like the idea of root sources for the arts. Unfortunately, this seems to fall into the “How Art Made the World” category, with collections of lights and whistles that purport to add up to an “answer” which amounts to more than random conjecture. My favorite responses were from jon_anon, which sounds like my better-informed colleagues in the music department, and “speedreader,” which sounds like 99.9% of my students.

  20. Whoa, wait, I can actually read this paper? THANK YOU!

    No, seriously; it’s so terribly frustrating to find research that’s been paid for by public funds, and yet is published through a private publisher who demands a less-than-meager sum to read it. Especially when it comes to academic papers: most publisher do little more than post a PDF on their website. The researchers went through all the work of preparing and formatting that document: they could have just as easily posted it on Scribd instead of sending it to a publisher.

    Kudos to Dr. Purves and Dr. Gill, as well as PLoS ONE for making these documents available to the world. Academia is there to help us all improve our knowledge, not just those with the money.

  21. I once read that there is even a scientific field called zoomusicology that deals with the musical contexts of animal voices (songs of birds, whales, wolves, …) and there relationship to music culture. I believe there is a direct effect/cause relationship between the evolution of local bird communities and their songs and the local music traditions. However, that’s impossible to prove and thus not science as well.

    1. You know, my grandfather called an old Kiss record “zoo music” once…

      Anyway, it’s easier to explain music’s habitual use and reuse of certain tones by demonstrating that most ideas humans come up with are derivative, and not wholly original. The ideas that are wholly original fail more often than not, mostly because the basics of good thought have been laid out for so long that there’s not much left to come up with from scratch.

  22. @technogeek

    “music is the enjoyment we take in counting without realizing that we’re counting.”

    that’s interesting. Where did you get that?

  23. Why are our scales often based on natural harmonics? well look at the simplest instruments: take the ancient brass instruments as an example, the Bugle being a modern equivalent: no mechanical anything about it, it works entirely on overtones (harmonic series) and this was the only way such instruments worked for many centuries. Stringed instruments work the same way (play a string, fret it halfway along it’s length, you get an octave up) and this relationship was obvious a couple millenia ago.
    Are we biologically tuned to these things? maybe but could that be because our ears use the same rules of physics that the instruments do?

  24. The five- and seven-note Western scales are not historically consistent either. Bach & co had to torque things pretty significantly to get us to this side of _Well Tempered Clavier_. The same scale sung in 17th c. chant is different from that scale as played on a modern piano, and the difference is microtones, which we can in fact hear and between which we can naturally distinguish.

    1. Ahh, the Well-Tempered tuning system. Let’s just see what a psychologically mal-adjusted Qwghlmian-Australian organist has to say on the subject …

      Waterhouse is going to fix the church’s organ. […]

      […] He is outraged and offended, after the service, when the powers that be are reluctant to let him, a total stranger and a Yank to boot, begin ripping off access panels and meddling with the inner workings of the organ. The minister is a good judge of character — a little too good to suit Waterhouse. The organist (and hence ultimate authority on all matters organic) looks to have been shipped over here with the very first load of convicts after having been convicted, in the Old Bailey, of talking too loud, bumping into things, not tying his shoelaces properly, and having dandruff so in excess of Society’s unwritten standards as to offend the dignity of the Queen and of the Empire.

      It all leads to an unbearably tense and complicated meeting in a Sunday school classroom near the offices of the minister, who is called the Rev. Dr. John Mnrh. He is a stout red-faced chap who clearly would prefer to have his head in a tun of ale but who is putting up with all of this because it’s good for his immortal soul.

      This meeting essentially becomes a venue within which the organist, Mr. Drkh, can vent his opinions on the sneakiness of the Japanese, why the invention of the well-tempered tuning system was a bad idea and how all music written since has been a shabby compromise, the sterling qualities of the General, the numerological significance of the lengths of various organ pipes, how the excessive libido of American troops might be controlled with certain dietary supplements, how the hauntingly beautiful modes of traditional Qwghlmian music are particularly ill-suited to the well-tempered tuning system, how the king’s dodgy Germanic relatives are plotting to take over the Empire and turn it over to Hitler, and, first and foremost, that Johann Sebastian Bach was a bad musician, a worse composer, an evil man, a philanderer, and the figurehead of a worldwide conspiracy, headquartered in Germany, that has been slowly taking over the world for the last several hundred years, using the well-tempered tuning system as a sort of carrier frequency on which its ideas (which originate with the Bavarian illuminati) can be broadcast into the minds of everyone who listens to music — especially the music of Bach. And — by the way — how this conspiracy may best be fought off by playing and listening to traditional Qwghlmian music, which, in case Mr. Drkh didn’t make this perfectly clear, is wholly incompatible with well-tempered tuning because of its haunting and beautiful, but numerologically perfect, scale.

      “Your thoughts on numerology are most interesting,” Waterhouse says loudly, running Mr. Drkh off the rhetorical road. “I myself studied with Drs. Turing and von Neumann at the Institute for Advanced Studies in Princeton.”

      Father John snaps awake, and Mr. Drkh looks as if he’s just taken a fifty-caliber round in the small of his back. Clearly, Mr. Drkh has had a long career of being the weirdest person in any given room, but he’s about to go down in flames ….

      [Source: Cryptonomicon by Neal Stephenson]

  25. I read about a similar study back in 2003–link here. One point noted in the older study is that the chromatic scale humans seem to prefer in music corresponds to physical resonances of sound waves in the vocal system, which would counter criticisms in some of the comments above that maybe we just emphasize certain tones in speech because we are predisposed to like those tones:

    The Duke researchers randomly extracted over 100,000 speech samples, each 0.1 second long, from recordings of thousands of English sentences. Acoustic analysis of the combined samples revealed 10 frequency peaks that match the most significant intervals used in musical scales worldwide.

    Moreover, the relative heights of the peaks backed numerous studies in which listeners ranked the harmoniousness of intervals. Speech in other languages – Mandarin, Farsi, and Tamil – also displayed the same pattern.

    The frequency peaks are caused when a sound wave from the vocal cords is shaped by resonances of the throat and oral cavity. The researchers say that, aside from animal calls, speech emanating from oscillations of the human vocal cords is virtually the only natural sound that we hear as tones.

    This fact, combined with the new finding that preferred musical intervals are better predicted by the acoustic quirks of the human vocal tract than by mathematics, leads the scientists to argue that the structure of music is rooted in our long exposure to the human voice over evolutionary time.

  26. I would have liked to hear more about microtonal scales. In my opinion most (though evidently not all) pentatonic and heptatonic scales don’t need much explanation, since they’re easily built using the circle of fifths and triads (i.e. frequencies in the simplest possible integer ratios).

    Once you got beyond the Western/Chinese twelve notes, though, I’m not quite sure what melodic or harmonic role the others would fill. Does a C-half-sharp add anything other than an extra flavor of dissonance? I would hope for a follow-up study, I guess.

    1. “Does a C-half-sharp add anything other than an extra flavor of dissonance?”

      We call that “soul” and you love it.

      1. Soul and blue notes are usually variants of other notes in the scale, though. It’s not the same as in true microtonal scales, where they have an independent existence within the same compositions.

  27. I’m skeptical of lots of PLos ONE articles. They’re not among the more stringent in terms of peer review.

  28. Explain to me why it makes sense that I love ambient field recordings, black metal, dance punk, math rock, classical, and electronic…to name a few genres. What about the fact that my musical taste progressively expands the older I get? I am finding my experience hard to pigeon-hole into this explanation.

    1. Actually I don’t think that it does. Listen, I like literally every type of music. I think we end up liking different tones later on in our lives based on what we heard in our early childhood. Who knows right? Did you know most babies can hear inside of their mothers by the time they are 6 months old? Here’s one of the weird songs I listen to. Even if you don’t like it or not, try to feel the first 2 minutes of it…

  29. Nobody here has mentioned the blue note, which is essentially a microtone and is quite familiar and even sounds pleasing to our ears. It’s very interesting the way the blue note imparts such a distinct feeling. Much of the best music of the 20th century– including the entirety of jazz, blues and rock and roll– is impossible without the blue note.

  30. @speedreader
    We used to have a Blackbird that sang the first few bars of ‘Chariouts of Fire’ before going off into his own song – no dope involved!

  31. I always watch when in a group of people listening to music, watch out for those who tap their feet or not. To me it’s amazing that the rythm doesn’t tap into ‘whatever’ in the brain and make you move. Some R&R is just cacophony, trying to mesh all instruments together, but say Latin american has me dancing to the beat. And the first time I heard Rock n Roll I was done. real real gone! But how can some people not respond to THE BEAT!!!!

  32. I think that this theory is likely incorrect for one main reason. That reason, is that the scales most people find sound “right” are based on simple fractional relationships between each note. This would imply that music is more about the geometrical relationships of the notes and not some arbitrary connection to human speech as it evolved.

    If music was based on speech alone, then there should be no rigid mathematical relationships between the notes. But since there are indeed these rigid mathematical relationships, it implies that music is in fact more about the math than speech. At least as far as pleasing tonal structures are concerned…

  33. “Any perceptual quality you have is there for some biological reason. They evolved because they provide useful information to us,”

    What a ridiculous statement. It’s the evolution equivalent of teleological thinking. Who is to say a given perceptual quality has any directed purpose at all.

  34. “Rock is especially popular because it emphasizes the musical intervals whose frequency relationships are those we hear in the human speech ,” Purves said. “That’s one of the reasons people like it so much.”

    Then why didn’t rock or something similar too it evolve much earlier in human history?

  35. Funny, I starting asking people why they liked what they like in music years ago – completely without method or rigor, periodically and at random – and the fact is, like scifijazznik says, a lot of people not only don’t care why they like what they like (or found it ‘troubling’ to consider why), but when confronted with being forced to decide upon a reason, have been unable to figure that out, even when prompted with a list of choices.

    What I do know for sure is, though, my musicology professor at U of Michigan, William Malm (now retired) hammered into our heads for the entire semester, every single class, the following statement:

    “Music is not an international language. It consists of a whole series of equally logical but different systems.”

    Also: Anonymous #14 states that you “like what you hear enough.” I do think that there is merit to that; people often like what they hear a lot of. But I wonder whether this premise affects people of all ages/cultures the same.. personally I feel like I know what I like, and it’s not what’s hammered into me 20x times a day by the generally craptastic current crop of FM radio stations. Assuming I took the time to listen to any of those stations long enough to hear the songs repeat.

    I would be interested to hear of some kind of psych? experiment where say, somebody paid a ton of teenagers to force a song they really thought was ‘cool’ on a bunch of their friends, even though they really hated it (and even more interesting, if it was clinically terrible), and attempt to track the popularity of the song through this process..

  36. Certain pitches contain a certain frequency. These frequencies can be found in a natural setting, and we have evolved to recognize them. Consonant sounds have a direct intervalic relationship between each other. It’s like 1/2 is a nice and neat .5. Dissonant sounds have a obsure or an non-intervalic relationship. Like 1/3 is .333333..ect.

    Scales are based upon nice and neat intervals. The 5th is actually a part of a note you’re playing in math. The pentatonic scale 5 (notes) is completly made of these stacked fifth intervals. root + 5th + 5th. These are the scales that have devoloped in various cultures around the world. Our human inflection often deviates in order to create an emotional response.A very interesting science.

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