From Jaws to Psycho: spooky soundtracks

What makes soundtracks sound scary, and what musical notes can creep us out most effectively? Janet K Halfyard, teaches courses on film music at Birmingham Conservatoire, and she gave Georgia Mills her top tips on making terrifying tunes...

Janet - I do an experiment with my students where I play them the same piece of film with different music. And music has a really profound ability to change the way we believe things are happening. So with this particular clip, it's a man and woman and in one version of the film with romantic music 'he's in love with her.' In the version, where I take some music from a horror film they always say 'he wants to kill her.' And it's the same clip of film so music has the ability to interpret the image for us; to anchor it into a particular meaning.

Georgia - Why do you think it has this effect?

Janet - Music works on us in a very profoundly psychological way. There are certain things we know about the world we live in from how we hear it. For example, horror film music uses extremes of sound so it will use very high sounds, it will use very low sounds, it will use very slow ones and extremely fast ones. And part of this is because of the way that this sound registers with what we know about what those sounds mean in the real world.

So, for example, with those really low sounds that you'll find in things like Danny Elfman's main title for Sleepy Hollow, which uses a great, deep kind of Russian choir voices and church organ. You have these very low sounds which tell us there is something enormous there because the bigger something is, the lower the sound it makes. And so having this idea of the enormous thing that you can't see, you can only hear. That's one aspect of how music becomes frightening.

Jaws is actually a prime example. You have those very, very deep string sounds - duh, duh, duh duh - and then it starts running towards you - duh duh, duh duh duh duh. So it absolutely is, you've got this huge thing that is lurking and then starts to run towards you and that's extremely frightening.

So one of the most effective horror music ever written. With the high pitch sounds, it's kind of like someone's screaming. Particularly because the high pitched sounds will quite often be discordant. They'll be clashing and jarring sound high up. And so you've got the Psycho stab cord from the shower scene going eek, eek, eek. It's these kind of shrieking, jarring sounds that tell us, again, somebody's screaming. That's the kind of the underlay of what's happening there.

 So there are these particular types of sounds, therefore, that say "this is frightening" to us.

Georgia - Are there any particular notes or chords that are just more scary?

Janet - Yeah. I mean, if you have two notes which are really close together in pitch and you play them together, they will kind of interfere with each other. They've got a set of frequencies purely, again, at the physical level, those frequencies will clash and beat against each other, and that's part of what will create that shrieking effect particularly when you have two notes played together very high up, they will really jarr against each other. And it's unnerving, it says again "this is wrong." So I think that's one of the big messages that horror music gives us is that things are going wrong.

I have to say, one of the biggest horror gestures is the use of silence - of actually having no music at all because then you've got no information.

Georgia - Firstly, that's a much easier job for the composer, I suppose?

Janet - Much, much easier for the composer.  But they can exploit it by having the music and then the music will suddenly stop for a very brief moment and then "wham", it kind of hits you with the scary stinger that makes you jump out of your skin.

Georgia - I suppose in nature we're used to it being noisy - bird song and things like that and  when it stops I guess something's gone wrong?

Janet - Something's coming, yes. I think a lot of the way that music in horror films works is to play on the way that we expect sound to work in the real world and yes, silence is really unnerving.

Georgia - So we've got silence, deep low sounds, and high clashing notes which can all make music more creepy. But apparently there's one interval, and that's the difference between two pitches, that has been used to scare us for over a thousand years.

Janet - Possibly the most important interval in horror music if there is a single musical sound which is something called a tritone - dum bah is how is sounds -  doo doo. And in the medieval period they called this the "diabolus in musica" - the devil in music. Because it was the most discordant interval that they knew of and it seemed, therefore, it was the disruptive thing - the devil in music. And composers have been using the tritone forever, in terms of evoking evil. You find in the The Simpsons theme as well...

Georgia - That well known horror!

Janet - Absolutely, but it's there to be disruptive, it's there to be discordant. It's like this constant wrong note. It's what makes The Simpsons theme so quirky. If you put it into a different context and it actually becomes scary - it sounds so wrong, so discordant that a lot of composers have written music that puts tritones in. It's like a weird angle, it disconcerts us and we don't necessarily know why, but we know that it's wrong.