Move over, math. The universal language is world music.

World music’s most striking feature is its diversity. A quick survey of modern musical styles demonstrates this variation, as there seems little in commonality between the melodious flow of jazz, the tonal jolts of dubstep, and the earthy twang of country folk.

If we expand our survey beyond contemporary genres, this diversity becomes even more pronounced.

Katajjaq, or Inuit throat singing, expresses playfulness in strong, throaty expressions. Japan’s nogaku punctuates haunting bamboo flutes with the stiff punctuation of percussion. South of Japan, the Australian Aborigines also used winds and percussions, yet their didgeridoos and clapsticks birthed a distinct sound. And the staid echoes of medieval Gregorian chant could hardly be confused for a rousing track of thrash metal.

Despite music’s far reach across cultures and time, its diversity has led many ethnomusicologists to proclaim the idea of a universal “human musicality” to be groundless or even offensive. But a new study published in Science has found evidence that the world’s musics share important acoustic commonalities, despite their apparent differences.

The researchers focused on vocal songs because it is the most ubiquitous instrument available to world music.

(Photo: Pixabay)

The universal qualities of world music

Samuel Mehr, who studies the psychology of music at Harvard, led a team of researchers in studying musical patterns across cultures. In their “natural history of song,” the team collected an ethnography and discography of songs from human cultures across the world.

The data set only looked at vocal performances because vocal cords are a ubiquitous musical instrument. They focused on four distinct song types: lullabies, dance songs, healing songs, and love songs. These songs were analyzed through transcriptions, machine summaries, and amateur and expert listeners in an online experiment.

The researchers’ analysis of the data revealed that these four music types shared consistent features and that cultures used in similar contexts. Some of the similarities were what you’d expect. Dance songs were faster and had an upbeat tempo when compared to soothing and slow lullabies.

But the researchers found subtler distinctions also shared across cultures. For example, love songs have a larger size of pitch range and metrical accents than lullabies. Dance songs were more melodically variable than healing songs, while healing songs used fewer notes that were more closely spaced than love songs.

“Taken together, these new findings indicate that some basic but fundamental principles mapping musical styles onto societal functions and emotional registers exist and can be scientifically analyzed,” stated cognitive biologists W. Tecumseh Fitch and Tudor Popescu (University of Vienna), who wrote the study’s perspective piece.

The study’s online experiment asked more than 29,000 participants to listen to songs and categorize them into one of the four types. The researchers precluded offering information that either explicitly or implicitly identified the song’s context. They wanted listeners to guess based on the song’s acoustic features alone.

The listeners, amateurs and experts, guessed the correct song type about 42 percent of the time, a success rate that stands well above the 25 percent odds of pure chance. The researchers argue that this shows “that the acoustic properties of a song performance reflect its behavioral context in ways that span human cultures.”

Far from tone deaf

Of course, we all know that music varies, and the study did find three dimensions that explained the variability across the four song types: formality, arousal, and religiosity. For example, dance songs were found to be high in formality, high in arousal, but low in religiosity. Meanwhile, healing songs were high in all three dimensions, and lullabies were the lowest.

“Crucially, variability of song context within cultures is much greater than that between cultures, indicating that despite the diversity of music, humans use similar music in similar ways around the world,” write Fitch and Popescu.

In addition, all of the studied songs showed tonality—that is, they built melodies by composing from a fixed set of tones.

To test this, the researchers asked 30 musical experts to listen to sample of songs and state whether they heard at least one tonal center. Of the 118 songs listened to, 113 were rated as tonal by 90 percent of the experts. These results suggest the widespread, perhaps universal, nature of tonality.

With all that said, the writers still recognize avenues of future research. They point out that the current database doesn’t explain the variance in societal contexts and acoustic variables. The vocal-only nature of the data also leaves an immense library of instrumental and rhythmic music unexplored. And as with any research into human universals, the database cannot hope to be comprehensive enough to support evidence from every human culture. Additional cultures and musical styles remain to be investigated.

However, Fitch and Popescu note, Mehr and his colleagues have provided a deeper understanding of a potential universal cognitive mechanism for music and a blueprint for future empirical tests.

“Today, with smartphones and the internet, we can easily imagine a comprehensive future database, including recordings of all cultures and styles, richly annotated with video and text, being assembled in a citizen science initiative,” they write.

The universals that bind us

Music is hardly the only human universal. Scientists have identified hundreds of cultural, societal, behavioral, and mental universals that have been identified among all known peoples, contemporary and historic. These include language, tool usage, death rituals, and, of course, music.

Study of fossils has discovered that Homo heidelbergensis, a common ancestor of Homo sapiens and Neanderthals, had the ability to control pitch (or “sing”) at least a million years ago. But having the ability in tandem with the cognitive capabilities to control it is another matter. Humans are the only Homo genus we know has met all the musical requirements, and we can’t be certain when these coalesced in our evolutionary history.

Additionally, archaeologists have found bone pipes made from swan and vulture bones dating back between 39,000 and 43,000 years ago. However, these were likely the result of a long creative process, likely preceded by instruments crafted by grasses, reeds, and wood, materials that are not as well preserved in the fossil record.

This makes it difficult to pinpoint when music entered our evolutionary history and therefore to pinpoint its evolutionary advantage. According to Jeremy Montagu, former musicologist at Oxford, one proposal is social bonding:

[M]usic is not only cohesive on society but almost adhesive. Music leads to bonding, bonding between mother and child, bonding between groups who are working together or who are together for any other purpose. Work songs are a cohesive element in most pre-industrial societies, for they mean that everyone of the group moves together and thus increases the force of their work. […] Dancing or singing together before a hunt or warfare binds the participants into a cohesive group, and we all know how walking or marching in step helps to keep one going.

According to anthropologist Donald Brown, despite human universals’ widespread nature, they result from relatively few processes or conditions. These include diffusion of ancient cultural traits or cultures meeting the demands of our physical reality. They can also stem from the operation and structure of the human mind, and therefore can result from said mind’s evolution.

Which is it for music? We don’t yet know.

The Science study authors suggest a picture emerging that music is an evolutionary adaptation—though, whether music is its own specific adaptation or a byproduct of other adaptations remains even more unclear. However, Montagu suggests a more cultural origin when he writes: “Each culture develops the tuning system that best suits its ideas of musicality. It is up to the cognitive scientists to determine why this should be so, but they have to admit, if they are willing to listen to the exotic musics of the world, that these differences exist.”

Further complicating the matter is the fact that while every human can appreciate music, not everyone can create it or even desires to (unlike language or other innate universals).