The sound of fear

The high-pitched scream of a violin under the frenzied see-saw of a furious bow. A murderous intent made manifest in melodic lines so sharp and jagged, a page of music looks like a threat. An ominous, low drone that grows bigger, louder, faster into an unrelenting sonic assault. Freeze? Fight? Take flight? Or, savour the sensations? 

The scariest movies in the world would be almost nothing without the music that makes them. Take away John Williams's infamous "dun-dun" and Jaws loses almost all of its anxiety-inducing dread. Without Wendy Carlos and Rachel Elkind's masterful theme — a chaotic and tension-filled reinterpretation of the "Dies Irae" section of Hector Berlioz's Symphonie fantastique — The Shining loses the deep foreboding that sets the stage for the domestic, patriarchal terror that follows.

So what is it about certain music that has the power to frighten listeners so profoundly? Vancouver-based writer, journalist and music lover Adriana Barton is the author of the best-selling book Wired for Music: A Search for Health and Joy Through the Science of Sound. She shies away from scary music and scary movies, but Barton finds it fascinating how much people love to be scared. 

"There's a whole population out there of people who seek out the creepiest, most sinister, most ominous sounds they possibly can find, and just love being scared out of their wits in the movie theatre," Barton told CBC Music over Zoom. "And I think that says something really neat about human nature."

Here Barton breaks down the sound of fear, and helps us understand how our brains process scary music.

Fear circuitry and Darth Vader

"The neat thing to me is that composers leverage the fear circuitry in our brains in various ways, and some of them are through learned associations, and some are through hardwired responses that we have to certain sounds. If we start with the hardwired part, listeners consistently associate low bass tones with dominance and power. So think Darth Vader, right off the bat: low, growling sounds tend to put us on edge and when we hear, 'Boom, boom, boom,' that's a nerve-wracking sound. 

"When the little bass tones become louder and faster, we experience them as aggression. The faster tempo stimulates faster brainwave activity in us, and our threat response really kicks in as if we are being chased. Jaws starts with a tuba and then it goes faster and faster and faster. And John Williams, the composer, has a great description of his own theme as 'grinding away at you,' just as a shark would do: instinctual, relentless and unstoppable. Each time that theme comes up in the movies, you've heard it before, and it will amplify that effect of a fear-inducing stress." 

Composer tricks

"Composers [will] take a familiar rhythm, like footsteps or a galloping horse or a ticking clock, and then play around with the tempo to frighten us in unexpected ways. So they speed up the familiar sound like the horse galloping and that will ramp up suspense. 

"On the flip side, sometimes the composer will suddenly slow down the pace of the rhythm. Like when there's a lull in the action, someone's hiding in a tool shed and you know, the demon or the monster will pounce at any time. But the eerie part is, we don't know exactly when that will happen. That sudden stopping of the rhythm that's familiar, that we expect to continue, puts us in a state of high alert. 

"There are intervals and harmonies like minor seconds and tritones — which are the augmented fourth — and minor ninths. And at a physics level, the dissonant sounds are more complex than consonant harmonies, such as perfect fourths, which gives them a cryptic unsettled quality, which is again perfect for raising anxiety in a film score. 

"Pitch is another way that composers ramp up tension. So we talked about how the bass notes convey power and aggression. On the flip side, when people get nervous their voices get high-pitched and squeaky and so composers leverage this feature and film scores in scary sounds by adding high-pitched violins or trumpets to rattle our nerves, and this is something I found was really interesting beyond the pitch, which is how high the note is. The tone quality matters too."

Animal screams and the amygdala

"The closer the music sounds to animal screams, the greater the fear factor. This was actually studied by a man called Daniel Blumstein, who's an expert in animal distress calls at UCLA. He was actually holding a baby marmot one day, and the baby marmot screamed, and it freaked him right out, so he had to go and study why. What he found was that when under threat, a screaming animal will tense its vocal cords, which creates high-pitched sounds that are raspy and unpredictable. And so scientists like him call it nonlinear sounds. And in the shower scene from Psycho, for example, screeching violins are nearly identical to these animal screams. 

"So, Blumstein and colleagues analyzed 102 film scores to verify the theory that composers scare us by tapping into our animal instincts. And they discovered that horror films often closely mimicked this rasping, jarring, unpredictable sound, signalling danger in the wild. And they found this in soundtracks such as The Exorcist and The Shining. And the movie King Kong, which was created in 1933, even went as far as to use actual animal screams.

"In neuroimaging, scary music really does stimulate the amygdala, which is an almond-shaped structure in the brain that is part of our early warning system in response to threat. So among the amygdala's key functions is to let us know when we have reason to be afraid. If the answer is 'Hell, yes!' the amygdala sends an SOS signal to the rest of us to get ready for fight, flight or freeze. 

"But now we have even stronger evidence that the fear factor in scary music is partly hardwired. In a 2005 study, researchers from the University of Montreal compared normal listeners with people who have had their entire amygdala surgically removed. These surgeries are a last-resort treatment for untreatable seizure disorders. And in this study, the listeners who didn't have amygdalas could still recognize happy music, because that doesn't stimulate our fear circuitry. But the listeners who lacked an amygdala could not identify which music samples were scary. And this was a task that listeners with intact amygdalas could do in seconds, they could instantly recognize scary sounds. So that shows us clearly that some of our responses to frightening sounds are indeed instinctive, but not all." 

Oversaturation and learned associations

"We learn to associate threatening phenomenon with specific sounds that we've heard before…. So maybe you've heard vintage horror soundtracks from the 1930s and 40s. They often play a rising succession of diminished seventh chords to evoke fear and suspense. But these sinister chord progressions were so overused that they became contrived and cliched. And so to modern ears, these scary chords would just as easily sound comical as creepy. So a learned association can change over time with different cultural associations or different life experiences.

"Here's another example. Nothing could be lighter than 'Singing in the Rain,' the Gene Kelly song in the 1952 romantic comedy of the same name. But when filmmakers set the very same song to a scene of ultra violence, in the 1971 film A Clockwork Orange, suddenly "Singing in the Rain" became horrifying. I still hear it as completely sinister, because of A Clockwork Orange, and I bet many other people do, too. So, again, composers play with these associations in what I consider to be ingenious ways. 

"Composers can use familiarity and then warp it in creepy ways to make that sound threatening. Our brain's frontal cortex is this prediction machine, so we're constantly comparing everything we see, hear or sense with everything we've experienced in the past. And we do this to keep ourselves safe, we're continually scanning our environment for signs of threat."