Vacation at the lake this past July. I decide I need to freak out my son. For science.

After swimming all day, the two of us huddle with my laptop and JAM5 speaker for his first viewing of "Jaws."

He's glued to the screen. I'm watching him. The tuba comes in almost immediately. 

Duuuuuuuuuuuuuun dun. Two notes that have been snaking through our collective consciousness for almost a quarter of a century. Duuuuuun dun.

After the endless parodies, maybe it's easy to dismiss as a cliche. I'm personally more terrified of "Baby Shark" these days. But watching my eight-year-old squirm like millions before him, it's impossible to deny John Williams has still got it. There's barely a glimpse of the shark for another hour, but already I can feel my kid's heart pounding. Literally, nothing has happened yet.

It's primal. Pavlovian. Spielberg famously couldn't show much of the great white because his prop sharks kept breaking. So kill after kill, it’s Williams’ two notes and racing strings that eat away at us. 

Now it's October—spooky soundtrack season! I love Halloween rock like the Misfits, the Cramps and all the kooky '60s novelty garage songs. But if we are talking about real scary music, nothing is as perfectly calibrated to mess with our minds as horror film soundtracks. 

My plan for this article was to show my son increasingly scary films and see when he broke (smart money was on somewhere between "Insidious" and "Babadook"). The boy's mother vetoed this.

Let's talk instead about what's happening on a sonic level with spooky soundtracks. I asked my friend Adam Hanson, who runs horror fan site FakeBloodClub.com, what makes for a great horror score? For him, it's all about foreshadowing. "It's something that guides your emotions down that path," says Hanson. "Whether it's a single wavering note that gives you goosebumps or something sinister and out of this world, the music should always serve the story and subconsciously be setting up the viewer for what lies ahead."

Hanson remembers his own early indoctrination. "Honestly, as a '90s kid, the intro to "Are You Afraid of the Dark?" used to spook me so much I'd have to hide behind the couch when I heard the first note. It's a slow creeping tune matched with great sound design and visuals. It's capped off with a haunting, ethereal vocal at the end. Freaky stuff for a show on Nickelodeon."

I'm far from an expert in theory, but horror composers are brilliant at building tension by playing with our inherent expectations of melody, chords and harmony. In Western music, everybody knows minor chords strike us as naturally sad. Shifting a single note in a classic root/minor 3rd/5th pattern darkens the mood, but as listeners, we also have deeply ingrained expectations of how chords progressions should flow. In popular music, the “tonic” of the dominant 7th often moves us from dissonance (instability) to consonance (stability) in a major key progression. The 7th note is only a half-step more to complete the nice, full octave. Peace, love and harmony!

Tension is created when you deprive listeners of that harmonic resolution. Delaying it creates musical suspension and it’s utterly maddening because your ears tell you it’s coming. The anticipation knocks the audience off-kilter subconsciously and is often used during early scenes where the coming terror is still creeping in the shadows unseen. (To wrap your head around dissonance, try this NYT piece: The Art of Setting the Senses on Edge.)

You may have heard of the Devil's Interval if you're a fan of metal or banned medieval music. It's a clashing tritone (root/augment 4th/diminished 5th) that sounds extra creepy because it seems to hang there, and our brains can't decide where it's going.

A frequently used example is "Danse Macabre" by the French composer Camille Saint-Saëns, which made an appearance all the way back in Jean Renoir's "The Rules of the Game" in 1939. The music holds up even if the effects don't.

Another example is in the opening of "The Shining," which features the Devil's Interval in electronic pioneer Wendy Carlos' creeping reworking of the Gregorian chant "Dies Irae."

Horror maestros will also throw in dissonant noise to frighten us as well. Like the jagged metallic chaos of "Texas Chainsaw Massacre." There is an evolutionary hypothesis for why this hits us so hard.

This TEDTalk by scientist Daniel Blumstein suggests that minor/irregular chords lack natural harmony in the same way animal screams do. We inherently perceive "non-linear" noise as environmental warnings that trigger our baked-in alert responses.

Think the shrieking string stabs of the "Psycho" shower scene. For years, some suspected composer Bernard Herrmann added screams of actual birds into the mix, but allegedly he achieved the effect by recording with incredibly close mics.

We typically think of horror soundtracks as instrumentals, but one of the GOAT horror music moves is to bring in the human voice. For his Oscar-winning score for "The Omen," prolific composer Jerry Goldsmith used a terrifying death choir. They are chanting in Latin, "We drink the blood / we eat the flesh / raise the body of Satan / Hail Satan / Hail Antichrist."

It's like Ronnie Jame Dio conducting Hell's own private glee club.

Harry Manfredini couldn't afford a full choir for "Friday the 13th." He created a theme for the mostly unseen killer himself by chanting, "ki ki ki, ma ma ma" with heavy echo (SPOILER: it's supposed to be "kill kill, mama.")

Italian prog weirdos Goblin took the use of horror vocals to a different level with their music for "Suspiria." Creepy whispers and howls intermix with synths and gothic guitars. It's a favorite of Hanson's. "Right out of the gate, it goes off the rails in utter chaos," he says. "From the creepy, twinkling lead melodies layered with hushed screams to the erratic tribal drums that go off at a moment's notice. It's completely disorienting."

Another fan of Goblin's work? John Carpenter who cited "Suspiria" as a major influence on his synth scores of the late '70s and early '80s. His "Halloween" theme set in pulsing 5/4 time is a minimalist masterpiece that's been endlessly imitated by "Stranger Things" and others. 5/4 is known as an odd time signature because it can’t be easily counted in nice even twos like most Western popular music. Again, messing with our ears’ standard expectations places us off-balance. It gives the music an “otherness,” and uses that extra beat to propels us forward.

Carpenter credited teenage bongo lessons from his music-teacher father for making him aware of the rhythm. The unrelenting momentum of the beat matches the masked killing machine of Michael Myers. (5/4 also at the driving heart of iconic pieces like “Mars, the Bringer of War” from Holst’s the Planets, the “Mission Impossible Theme” and the Dave Brubeck Quartet’s “Take Five”). 

In a genre thick with homage, ideas tend to spread like zombie viruses. Hans Zimmer and sound designer Mike Zarin have fought over who should get credit for inventing the "BRAAMMM" that's become inescapable in the last decade. But just as monsters are always evolving, horror soundtracks keep pushing into new unsettling soundscapes.

For the original "Alien," Jerry Goldsmith added unique otherworldly textures with Indian conch horn, didgeridoo, steel drums, a serpent (a giant twisting horn from the 1500s) and echoplexed plucked strings.

It's challenging to identify what instruments are making what noises, perfectly capturing the terror of the xenomorphs. Director Ridley Scott also reused atonal passages from Goldsmith's earlier work on the film "Freud" to creepy effect. 

What are more recent examples of great horror music that’s pushing into new directions? "It Follows" from 2014 features an electro-creep score that's rich in mysterious textures. The DJ/producer Disasterpeace creates a strange, stalking intensity that fits the "what the hell is?" atmosphere of the movie. Icelandic composer Jóhann Jóhannsson was just starting to build a body of film score work before his untimely death in 2018. His unearthly music for "Mandy" and "Arrival" are both steal-your-breath tense and yet, oddly pretty.

Hanson recos the recent work of avant-saxophonist and composer Colin Stetson on films like "Hereditary" and "Color Out of Space," which he praises as "just absolute unnerving and bleak." Stetson knows about discovering uncharted noises, having played as a sideman with Tom Waits, Godspeed You Black Emperor, Animal Collective and TV on the Radio. "I got to see him perform solo a handful of years ago and it was mesmerizing," Hanson says. "He plays this gigantic bass saxophone, and with various mics hooked up the instrument and one around his throat, he's able to create these wild and hypnotic pieces."

Another new classic is the score for "Under the Skin" by Mica Levi. Instruments seem to twinge, stretch and then melt as they hit your ear. (SPOILERS) It mirrors the mind-warping journey of Scarlett Johansson's alien creature as she rampages across the Scottish countryside. It’s a fun inversion of the horror trope—the beautiful waif is actually the slasher in disguise devouring farmers. 

And that is why we keep coming back to horror music. These soundtracks are terrifying roller coasters. Half the time we’re scared of clacking up and up the ramp, soiling ourselves because we know what’s next. The rest of the time we’re in utter shock as those same expectations are flipping us on our heads. You can close your eyes and hang on for dear life, but the sound always gets you to the end.

Happy Halloween and stay spooky, kids!