In this Quick Tip we're going to emulate a theremin sound using Ableton Live's Operator (although the same principles apply to other synths as well).
The theremin (named after its Russian inventor, Professor Leon Theremin, who patented the device in 1928), often viewed to be the first electronic instrument, has two metal antennas which sense the position of the player's hands (it is played without contact from the player), who can control oscillators for pitch (frequency) with one hand and volume (amplitude) with the other. A similar device is the Ondes Martenot, with the main addition of timbral controls, switchable loudspeakers, and a keyboard.
Many people just call it "that ghost thing sound you hear in old horror movies". Although that is quite true, it has also been featured in classical music, modern film music, rock, etc.
The idea is pretty simple: sine oscillator, slow attack, one voice (monophonic), glide between notes, and vibrato.
So this is what we're going for:
Step 1: Synthesizing the Sound
Open a new instance of Operator and leave the Wave to "Sine". Set the filter to "Band 24 dB" (perhaps the most suitable filter, but make your own choice if it doesn't fit your taste), and lower the Frequency to about 350 Hz. Lower the "peak" value down to -inf dB, to get a slow, very smooth attack.
Click on the "Time-Tone-Volume" tab and select "Voices: 1", since the theremin is a monophonic instrument.
Let's add some Vibrato. It'll give us a more convincing theremin sound (some might say spookier). I like having the LFO at Sine, the Rate value at about 80 and the Mod value at about 15%. But experiment with different values until you have the one you like the most. After all we can connect those two knobs to some macro controls and tweak them as we wish (that's what we'll do later).
Enable "Glide" to have the notes connect slowly when played legato. Let's set the time at about 70 ms.
Now let's try something out with Operator's Pitch options. By lowering the pitch envelope down to -100%, the "peak", "sustain" and "end" values down to -12 steps and the "initial" value to +48 steps (slow attack at about 300 ms) we get a cool gliding effect when playing the first note:
Step 2: Polishing the Sound
What I personally don't like about that sound some times, is that it can get too intruding within a song's mix. I like cutting some of the more "harsh" frequencies, depending on the song and music of course.
Ableton's "Spectrum" plug-in can be quite helpful in this situation, making it easier to recognize the Hz values of the frequencies we want to reduce.
For those who don't use Ableton Live, you can try out a freeware program called Blue Cat's FreqAnalyst, available for both Windows and Mac users. I usually cut around 370 Hz (Low Shelf) and do a slight LowCut at about 100 Hz, using the EQ Eight plug-in, like this:
Try adding a slow Autopan plug-in with a 360 phase, making the vibrato effect a little more dramatic, and increase Operator's Spread knob to 50% if you want it to sound more stereo and wide. We could "polish" the sound a little further by adding a subtle Delay effect, and a Compressor and Limiter to even out the volume levels.
Step 3: Performance and Expression
It sounds nice, except the fact that we haven't really set any knobs and values to be controlled in real-time while playing. The attack values (change of volume with one hand) for example are usually altered all the time during a theremin performance, and the pitch can get quite crazy and unstable in purpose. By grouping the racks into an Instrument Rack, we are able to map some Macro Controls to knobs like Volume, LFO Rate and Mod, and Transpose.
Keep in mind that you can program the Min and Max values of the Macro Controls, by pressing on the "Map Mode" button and changing the values as you wish.
If you program your melodies and don't play them via keyboard, MIDI-automations are quite simple to program with your mouse.
Right click and select "Show Automation In New Lane".
You can either draw the automations (Ctrl-B) or set and transpose points with your mouse.
And here it is used in the context of a mix.
I hope you found this tutorial useful. Thanks a lot for reading! Don't hesitate to leave a comment with any suggestions, questions or requests.
Happy music making!
- Ableton Live Source Files