Music Changes the Way

Hum the first two notes of “The Simpsons” theme song. (If you’re not a Simpsons fan, “Maria” from West Side Story will also do.) The musical interval you’re hearing—the pitch gap between the notes—is known as a “tritone,” and it’s commonly recognized in music theory as one of the most dissonant intervals, so much so that composers and theorists in the 18th century dubbed it diabolus in musica (“devil in music”).

Now hum the first few notes of Twinkle Twinkle Little Star, or, if you prefer something with a little more street cred, the “I’m sorry” part in Outkast’s “Ms. Jackson.” This is the “perfect fifth.” It’s one of the most consonant intervals, used in myriad compositions as a vehicle of resolution and harmony.

Is it possible that hearing such isolated musical components can change the way you think? An ambitious new paper recently published by Jochim Hansen and Johann Melzner in the Journal of Experimental Social Psychology argues precisely that. The researchers brought pedestrians into a laboratory and played them a short, stripped-down piece of music consisting of a series of alternating chords. Some people heard chords including the tritone; others the perfect fifth. A couple other tweaks were also made: in the tritone condition, the chords were played slowly—only once every four-beat measure—while in the perfect fifth condition, the chords went by rapidly, sounding every beat. Further, a “reverberation” effect was added such that the tritone chords sounded like they were being played in a cavernous cave and the perfect fifth chords in a carpeted closet.

What the scientists found is that the simple act listening to either of these two chord sets changed how people processed information in a very basic way. For example, the researchers asked people to take a list of shopping items and organize them into groups. Think detergent and paper towels: same kind of thing, or different? Results showed that “tritone” people formed fewer categories than “perfect fifth” people, indicating that they were thinking in broader, more inclusive categories than their counterparts.

In a separate measure, the scientists asked people to imagine buying one of two imaginary toasters. These toasters varied in what is known as “aggregated” versus “individualized” information. Do you know how on you can learn the average star rating of a given item? This is aggregated information; it’s pooled from a wide range of sources. Individualized information, by contrast, would be the customer reviews that appear at the bottom of the page. Which do you pay more attention to when these give conflicting messages—when, say, the aggregated information is largely negative but there is a single glowing customer review? Turns out that people who are exposed to “tritone”-type music samples are more likely to be swayed by aggregated information, and “fifth” people by the reverse.