How to make ghost sounds with a theremin-style sine wave and whistling

Okay, so what does a ghost sound like?

For most of us, it’s a theremin. That wobbling, sliding electronic tone has become one of the most iconic sounds in film music. The good news is you don’t need to own one to get the sound. In this guide I’ll show you why it works, how to fake it with a single sine wave, and how to make ghost vibes out of your own whistling, however bad your whistling is.

A very short history of the theremin

The theremin is an electronic instrument created in the 1920s by a Russian physicist called Leon Theremin. A few moments in film history are worth knowing, because each one teaches you something:

• Shostakovich, Odna (1931). One of the earliest uses in film. He used it to convey confusion and disorientation in a snowstorm. I love the idea of those wobbly electronic notes representing confusion.
• Miklós Rózsa, Spellbound (1945). Arguably America’s first mass exposure to the instrument. It shows off the theremin’s subtler, ethereal, voice-like side. I think that’s one reason it works so well as a sound for ghosts: it sounds like an unearthly, distant, disembodied voice.
• Bernard Herrmann, The Day the Earth Stood Still (1951). Here it isn’t ghosts, it’s the otherworldly, the unexplained, the alien. All still perfect for horror.

Thanks to Herrmann, and later Danny Elfman’s Mars Attacks!, the theremin got tied to sci-fi. But it’s stayed a staple of horror too.

My own first taste of that spooky ghost sound was the library scene in Ghostbusters, scored by Elmer Bernstein. That wavering voice is actually the theremin’s cousin, the ondes Martenot, which tells you something important: it’s the qualities of the sound that matter, not the instrument. I fell for the ondes Martenot properly in my twenties, through Jonny Greenwood’s score for There Will Be Blood, especially “Prospectors Arrive”.

The five ingredients of a ghost sound

Both instruments share a few qualities, and once you know them you can build the sound on almost any synth. You need:

1. A synthetic sound. Pure and electronic.
2. Vibrato, preferably one you can control.
3. A slow attack, so notes fade in rather than start.
4. A slide between notes, called portamento or glide.
5. Some reverb, just for fun.

That’s it. Let’s build it.

Building a ghost from a simple sine wave

I start with a sine wave because it’s the purest, almost completely clean electronic tone. Most synths can make one. I used Logic’s ES2, but any synth with a sine oscillator, an envelope, glide and an LFO will do it. If you want something free, Vital and Surge XT both fit the bill.

1. One oscillator, sine wave. Switch off any other oscillators so you’ve only got the one.
2. Slow attack. Turn the amp envelope’s attack up so each note swells in.
3. Mono and legato. Set the voice mode to mono with legato on. This is what makes the slide work properly when you overlap notes.
4. A little glide. Add a bit of portamento so you slide from one note to the next. Overlap your MIDI notes so the glide triggers.
5. Vibrato. Route an LFO to pitch, or use the mod wheel to bring vibrato in and out. Don’t skip this.
6. Check the tail. If notes hang around too long or cut off oddly, adjust the release until it feels right.
7. Reverb. I chuck a plate reverb on it. Plate is uncoloured and gives you a feel of space without putting you inside a particular room.

The vibrato really is the key. It gives you that wobbling-in-the-air feel. Try playing your line with and without it. Without vibrato it still works, and sounds more like the ondes Martenot. With it, you’ve got your ghost. Vibrato for the win.

Give your ghost some music

Ultimately we want to make music, we don’t want to just make noises like ghosts. Although that is a lot of fun.

So put something underneath it. I wrote a simple minor waltz on piano: C minor to Ab major to G major, which is i, VI, V in C minor. Then I just improvised over the top with the sine patch, sliding between notes and leaning on the vibrato. I absolutely love it. A simple progression and one sine wave is all it takes.

Ghost vibes from whistling

Now for something you can’t get from a sample library: you.

I can’t whistle well at all, so I take this away from a traditional melodic approach and the quirky Tim Burton sort of sound, and towards a tense horror sound bed. Here’s how.

Step 1: whistle a drone bed

Record a few takes of yourself whistling one long note, like a drone. Then stack them on top of each other as a choir of whistlers. Normalise the takes.

It might sound awful, in which case, great. Listen closely and you’ll hear something wonderful: beating. It’s the same wobble you hear when you tune an instrument and two notes are slightly out of tune with each other. That beating is tension. You can actually hear it.

Loop a couple of the best takes to stretch the bed out to a minute or a minute and a half.

Step 2: clean it up

• Cut the lows with a high-pass filter. Whistling picks up rumble you don’t need.
• Add some reverb.

Step 3: whistle a simple melody on top

Keep it slow, with only a few notes and not much movement. Wobble your tongue to add your own vibrato. Record a couple of takes and layer them. They won’t match perfectly, and that’s the point.

Step 4: take it out of the world of whistling

At this stage it’s still obviously whistling, so it isn’t really ghost vibes yet. If you don’t want something to sound like its source, you’ve got to change it in some way.

• Pitch shift it down. This alone takes it out of the world of whistling and makes it something else. A pitch-shifting plugin such as Pitch Monster will do the job.
• Double it an octave below to add weight without making it too dark.
• Put it in a big space, as if it’s in a cathedral.
• Run the top line through a tape or cassette effect for an old, vintage feel. I used a cassette plugin; MISHBY is another tape machine effect you could try.

Out of tune is good

This is one of the reasons I absolutely love horror. For once I can play and not worry about being in tune. In fact, the scarier the better.

And because it’s your whistle, it doesn’t sound like anyone else. There aren’t many samples of me whistling anywhere.

Wrap-up

A ghost sound is a pure tone, a slow attack, a slide, a wobble and some space. Build it from a sine wave, or build it from your own slightly out-of-tune whistling and mess with it until it stops sounding like you. Then put it over some real music. Go and have some fun with that sine wave.

Happy composing! Rich