Is Western Musical Taste Hardwired? Probably Not, Say Neuroscientists

So much of music consists of fundamental-seeming rules and patterns.

To see this, consider that there exists a noisy ether of disordered acoustic frequencies permeating our world (everyday background noise, that is) and that we can make pleasing tones from this din simply by restricting those chaotically distributed frequencies to those of musical notes.

You could record an actual bull in an actual china shop and then filter that audio so that only sounds of the frequency 440 Hz would pass through, along with perhaps several integer multiples of that frequency, and this would sound nice. You could then readjust your filter so that notes of the frequency 554 Hz (four semitones higher than 440 Hz) pass through as well, and you would hear a musical "third," which will also sound nice. Or you could readjust it so that 523 Hz sounds pass through, which will be a "mysterious"-sounding minor third.

At any rate, this goes on and on and on. But despite the appearance of so many elegant rules of musicality, we still don't really know why we find some sounds more pleasing than other sounds. Is this hard-wired into our brains? A new study published in Nature from researchers at MIT and Brandeis University suggests that the answer is no. The authors considered the reactions of 100 members of a remote Amazonian tribe having little to no exposure to Western music—to sounds that are generally considered to be consonant (pleasing) or dissonant (noisy)—and found that they showed remarkably little preference. The suggestion is that appreciation for conventional (to us) musicality is something acquired via exposure to Western music.

Consonance is at the heart of most of our musical rules. It occurs when we play notes together that can be reduced to simple integer ratios. The aforementioned third occurs when the frequency ratio of two notes is 5:4. A musical tritone, aka the "Devil's interval," has a frequency ratio of 45:32 and is thus very dissonant. The higher the numbers in the ratio, the less resolution there is and the more unpleasant the sound, at least to our Western brains trained on Western music.

"The contrast between consonance and dissonance is central to Western music, and its origins have fascinated scholars since the ancient Greeks," the current study notes. "Aesthetic responses to consonance are commonly assumed by scientists to have biological roots, and thus to be universally present in humans. Ethnomusicologists and composers, in contrast, have argued that consonance is a creation of Western musical culture. The issue has remained unresolved, partly because little is known about the extent of crosscultural variation in consonance preferences."

The Tsimane people are a society of horticulturalist-foragers that live in a region of Bolivia so remote that the only means to access it is via canoe. There is no radio here or television or, for that matter, electricity. They are of particular interest because harmony, polyphony, and group performances are conspicuously absent from the Tsimane's music. The natural hypothesis is that they experience consonance and dissonance differently than Western listeners.

Example sounds.

This hypothesis was tested by examining three groups of Bolivians (urban, rural, and Tsimane) and two groups of US residents consisting of musicians and non-musicians. All participants were played music over headphones featuring varying levels of consonance and dissonance and then asked to rate the pleasantness of each piece. The American participants mostly reacted positively to the consonant music, with musicians reacting more positively than non-musicians. Bolivian city- and town-dwellers were also more into consonant music, but a bit less so. The Tsimanes, meanwhile, rated consonant and dissonant music as equally pleasant.

You can see the results below, where the asterisks denote relative statistical significance. (The laughter/gasp component was introduced to probe for possible misunderstandings among the groups with respect to listening instructions.)

These results were supported by a second round of experiments with different populations based on Tsimane' vocalist-sung music digitally manipulated in different ways to sound more or less consonant. Even though the music was very different in many ways from Western music, the Americans responded positively to Tsimane music that had been altered to display consonant characteristics, which is pretty interesting. Again, the Tsimane did not prefer consonance even when it was their own remixed music.

Worth noting is that while the Tsimane's music may be dissonant, it is not disordered. There are scales underlying it, and within those scales are relations that likewise resolve to simple integer ratios. The development of tonality, generally, is hardly arbitrary and though the Tsimane music is dissonant with respect to Western scales, it is not chaos. We can see in the charts above that both US and Tsimane listeners were turned off by tonal roughness, a property that occurs when two tones are played that are very near each other in frequency.

"Although many questions remain, this work represents an important contribution to our understanding of how the diversity of human cultural expression can influence perception," Robert Zatorre, a neuroscientist at McGill University, offers in an accompanying Nature commentary. "More generally, it provides clues to how the environment interacts with the nervous system to produce all manner of complex behaviours, feelings, and thoughts."