You’ve heard the Theremin as a sound-making instrument. But it can be a MIDI controller, as well – an extremely sensitive and expressive one. Continuing our DIY round-up, here are the details in case you’d like to try it yourself.

When we last heard from Sarah Angliss and Spacedog, we were introduced to their creepy Theremin-playing doll Clara 2.0. Now, they’re using the Theremin as an audiovisual controller, triggering audio and video samples from the 1968 film The Devil Rides Out and my personal favorite, a parakeet training record. The result is a new version of the ballad “Willow’s Song” cult classic The Wicker Man (1973). (Wikipedia understands if you don’t.) Here’s a live performance of the result:

I figured readers might want to know more about how to use the Theremin as a controller, so I asked Sarah for more details.

Live theremin AV controller
in Willow’s Song (Hammer sandwich mix)
Here, you’re watching a song featuring Spacedog’s theremin AV controller. The Hammer samples are being scrubbed (i.e. speed controlled) live using the theremin. I’ve devised a Max/MSP patch that enables me to do so – this also scrubs the video live. Mike (in the green tee-shirt) is cueing in the samples as the song progresses.
As the lighting in the gallery wasn’t suitable for projection, we’ve added our usual visuals onto this film, during the edit (sorry – we know that’s cheating). If you want to see the real thing, do come along to one of our live shows. 🙂
This number samples the Hammer classic The Devil Rides Out (1968), mixing it with Jenny’s live rendition of the Willow’s Song from that other British occult classic The Wicker Man (Paul Giovanni, 1973).  The very first sample is from a 1950s Parakeet training record.
The line-up: Jenny Angliss (vocals), Sarah Angliss (theremin and AV scrubber), Ben Kypreos (guitar), Mike Blow (cueing samples), Colin Uttley (camera)
Technical details
All theremins give you a single tone with a varying pitch and volume. Put that into software, such as Max/MSP, that enables you to analyze frequency and volume in real-time and you have the basis of an AV scrubber. I simply hook a continual frequency measurement up to the groove~ control in Max sound and the rate control of a Jitter video to turn my theremin into a highly theatrical AV scrubber that I can use, live, during a song. I do some maths on the frequency measurement so a doubling in frequency, as I go up an octave on the theremin, doubles the speed of the audio and video.
There are various ways to measure frequency in real-time. Fortunately, the theremin creates a waveform that’s highly predicable so it’s easy to use techniques that rely on zero-crossing.
If your theremin has CV out, then you have something very useful – a voltage that you can measure directly and that’s proportional to pitch. You can use this to control just about anything, from lights to music, for instance using a Phidget or Arduino board.
I prefer to steer clear of anything to do with midi because, as a thereminist, I like all the ‘flexible’ (i.e. wobbily and inaccurate) tuning that’s part of the instrument’s character. As midi will quantize your pitch into neat, whole numbers, I think using midi with a theremin is missing a trick. But I realize that’s down to personal taste.
I suppose the hardest and most important bit is to find the right samples to create a really good effect. But then that’s the case, whatever controller you’re using.
Happy thereminininining!
Spacedog UK


Used the Theremin in other ways? Got your own controller scheme? Let us know.

  • David Cake

    Sounds like from that description she isn't using it as a MIDI controller at all, but going direct from theremin signal to AV control in Max without using an intermediate format like MIDI at all.

    She mentions a theremin with CV out as being highly desirable – the PAIA Theremax is an excellent example.

  • Yes, the Theremax works very nice from the CV output. I have my whole "Live Electronics" Setup centered around a Theremax, and it enables me to play along with a 30-piece Modern Jazz Big Band. The dramatic changes in Volume, Pitch and Harmonic content created by 30 "real" instruments during a freejazz improvisation phase are really something one has can not cope with "just" a computer and a keyboard.

    My Theremax Audio goes into a SHERMAN 1 filter bank (this is nice because it has a "noise gate" functionality across the input), and I use the (distorted) Audio as well as the control signals from the Sherman to mix and control a variety of plugins inside Ableton live, which acts more or less only as a VST host. The VST in use are NI Guitar Rig, Reaktor, with a KORE 1 controller for scene recall. The Audio Interface is a M-Audio Ozonic, this is essential as it has 4 mixable Audio Outputs, OUt1+2 are the Mixer outs, OUt 3 is Pre-Fader Theremin for constant retuning, and Out 4 is a Post-Fader Effect Send to a old Multieffects hardware device.

    In further parallel connections, I route the Theremax CV out into a custom-made MIDIBOX analog IN to create MIDI Control changes, and the Theremax Audio Out also into a vintage IVI Pitch Rider to create MIDI Note-On Messages (the IVI also creates very nice Pitch Bend Messages).

    I would love to point you to a schematic, but I am rearranging it for each concert and as such never found the right time to map it out…

    I will post some images on my blogpages.

    Happy "Theremining", karl.

  • If you have a spare mono input, a cable, and some conductive material you can make your own theremin-style control device with very minimal effort by normalizing the amplitude of the mains hum. Last winter I tried this with some tea. I wasn't feeling particularly creative and just used the control signal to control the frequency of a cycle~. And if you have a spare stereo input, you can even make a 2d controller!

  • I've been using an VST plug in called WIDI audio to MIDI.
    It's available as an audio unit as well.

    I use the plug-in in Live…Live accepts the audio input from the theremin and this plug-in converts

    the audio to MIDI data, which I route to another

    track with a MIDI synth…does that make sense?

    It works pretty well, but is VERY sensitive.

    It's difficult to get specific notes because they are very close space-wise…I had thought about trying to re-map the synths to compensate for this…but I'm not sure how…maybe someone can help.

    Best, Scott

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