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Music is universal — but the way it makes us feel may not be

A Tsimane man in Bolivia participating in the music experiment. (Josh McDermott)

The interval is called "the devil in music" because of how it sounds: unpleasant, unsettling, even scary. It relies on two notes separated by three steps, creating the dissonance known as a tritone that composers for centuries have used to great effect.

You hear the sound in the pagan scene of Wagner's "Götterdämmerung," the intro to Jimi Hendrix's "Purple Haze," the theme song from the "Twilight Zone," in movie scores the moment the villain arrives. And you know immediately that you're supposed to feel unsure and apprehensive. The dissonance is so eerie, so deeply unsettling, that musicians have long believed our dislike of it is innate.

But if you grow up among the Tsimane, an isolated society in the Bolivian Amazon, you might have no problem with the tritone. Uninfluenced by Western musical tastes, the Tsimane (pronounced chi-MAH-nay) have no preference for consonant chords over dissonant ones, researchers reported Wednesday in the journal Nature.

"People tend to assume that features of music that are present in Western music have some kind of fundamental importance, some biological basis," said Josh McDermott, an auditory neuroscientist at the Massachusetts Institute of Technology and lead author of the study. "But this result that suggests that isn't the case."

There's no absolute definition for consonance and dissonance; the terms mostly have meaning in relation to each other and in cultural context. Consonant chords are generally heard as happy, triumphant or sweet — think of the major fifth in the "Star Wars" theme and the major triad in "Ob-la-di, ob-la-da" — while dissonant ones are the opposite. Often, we talk about the former in terms of "stability." The brain wants to hear dissonant sounds, which feel tense and unstable, resolve into consonant ones: In "Maria," from "West Side Story," the dissonant first two notes (C and F sharp on "Ma-ri," which form a tritone) resolve into a consonant one (G, which forms a perfect fifth with C).

You can hear the difference in these two tones:

The dichotomy has some mathematical logic. The notes in consonant chords vibrate at frequencies that are nicely proportional to one another — a perfect fifth has the frequency ratio 3:2, a major third is 5:4, an octave is 2:1 — while the frequencies of dissonant chords form weird ratios. The Greek mathematician Pythagoras figured this out in the sixth century B.C. (nothing says "Western culture" like invoking ancient Greece), and European composers have pretty much stuck with it ever since.

"That's one of the main reasons why people have been convinced that there’s sort of a biological and physical basis" to our preference for consonance, McDermott said. "Because of those mathematical relationships."

In a study that took them from cities in the United States to villages in Bolivia only reachable via a days-long canoe trip, McDermott and his colleagues surveyed more than 250 people to test the centuries-old theory. They found that preference for consonant sounds correlated directly with exposure to Western music. Music students in this country are highly likely to judge them as "pleasant" and dissonant sounds as "unpleasant" — but Americans without musical training slightly less so. City and town dwellers in Bolivia also showed a preference for consonance, though it was much less pronounced than that of Americans.

Yet when McDermott and colleague Ricardo Godoy, an anthropologist who has been working with the Tsimane for 20 years, visited the isolated Amazon community, they found something much different.

"The experiment was very simple: We just had laptops and headphones and a gas generator, and we played these sounds and asked them to tell us whether they liked it or disliked it," McDermott said. "And they rated [consonant and dissonant sounds] equally. They had no preference."

This wasn't because the Tsimane don't recognize the distinction; when asked, the participants were able to identify which chords were which. Control tests using sounds typically considered unpleasant — a gasp of fear, the "rough" sound of two tones that are close together in frequency — also demonstrated that the participants shared other supposed "universal" preferences.

"Rather than being an inevitable consequence of auditory system biology," the researchers conclude, "it seems that the preferences exhibited by Western listeners for harmonic frequencies arise from exposure to Western music."

All known cultures make music. The desire to string notes together into something like a melody seems to be innate to humans.

But this study and others suggest that the melodies we prefer may not be quite so universal. For example, the Tsimane don't have a background in musical harmony — their musical traditions don't involve playing multiple notes at the same time, and when encouraged to play or sing together, they demurred. In an accompanying analysis in Nature, neuroscientist Robert Zatorre suggests this might explain the Tsimane's lack of preference.

"I think that our results really underscore the degree of variation that exists across cultures in terms of how people hear and evaluate music,"  McDermott said.

That variation is "masked" by the ubiquity of Western music, he said — nearly everyone with access to a radio and an Internet connection is now immersed in music that associates consonance with triumph and dissonance with fear. Meanwhile, cultures like the Tsimane's are increasingly at risk of disappearing. McDermott might not be able to repeat this study a decade from now.

The research "underscores the importance of culture in how people hear music, but also underscores the importance of exploring non-Western culture," he said. "And that's getting harder to do."

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