Just in case mastering the subtleties of playing a Theremin isn’t hard enough for you, you’re in luck: you can master the subtleties of building a robot that has to then master the subtleties of playing the Theremin.

Sarah Angliss, a human Thereminist in the UK, sends us this video of a creepy doll robot playing the Theremin. (If you’re prone to the jeebilies, you may not want to watch. Sarah writes, “I’ve posted my latest jam with Clara 2.0, the theremin playing robot doll, on YouTube. Hope you enjoy watching her talents (or lack of them).” (Technical details after the jump.)

Our friend Ranjit promises this week he’ll bring his Theremin-playing bots to Handmade Music, so if you’re in the NYC area and free this Thursday, you can meet them in person. If not, here they are on YouTube playing “Crazy”. Ranjit describes thusly:

ROBOT BAND! LEV the thereminbot and his newly-built pal thumpbot play “Crazy” with help from a 20-year-old MT32 synthesizer. OK, Lev’s a bit out of tune, but hey, ROBOTS. A tribute to The Ether & Aether Experiment’s marvelous performance.

I don’t know. I’m nervous. I think we’d better whip up some Theremin Laws of Robotics quickly. (Wait — on second thought, those conflicting laws don’t work out very well, do they?)

More technical details on how Sarah pulled off her creeptacularly brilliant robo-Thereminist:

First, from YouTube:

Named in honour of the original theremin virtuoso Clara Rockmore, Clara 2.0 is a robot doll who can play the theremin live. I call her the ‘polite robot thereminist’ as she listens to a line from another player and moves her dolly arm to get her own theremin in perfect tune. Well, that’s the theory…

In this jamming session, Clara 2.0 is copying a line from an old Roland SH-2 synth (which I play silently), then the line from my own theremin. When the two theremins play together, it gets quite chaotic as Clara tries to follow me – and I try to lock into Clara’s line.

As Clara 2.0 is continually monitoring a live sound and adjusting her tuning (no midi here), her technique has the fluid pitch of a human player. Everything on this recording – apart from the drum track – is played live. There is no manipulation of the recorded sound, apart from multitracking and a little reverb after the event. The keyboard instrument at the beginning is a cheapy toy, called an Angel Organ – I hope you can forgive its cranky tuning. The final theremin melody has been treated, live, with an old-school vocal flanger.

Clara is under continual development – she has quite a way to go before she can claim the talents of Lev (a great robot player). Keen-eyed observers may have noticed the wobbily thread of wire on the end of Clara’s egg whisk. This gives her some Rockmoresque vibrato.

I do attempt to incorporate Clara 2.0 into my stage act although she can be temperamental. Recently, I’ve been trying to improve her earthing and capacitance so she can be set up swiftly and can work more reliably ‘out of the box’.

Thanks to everyone at Dorkbot London and the Hands off Festival, 2007, for their encouragement and useful tips. In particular, I’d like to thank theremin maker Jake Rothman for his extremely useful electrical advice (Clara’s insides are now lined with silver foil) and Gordon Charlton, whose virtuosic egg whisk numbers inspired Clara’s current look. Thanks also to Emmet Spier for screwing her arms on better, Mike Blow for suggesting I try out this classic tune and Colin Uttley for playing the bass riff. Apologies to the great Roy Budd, composer of the jaw-droppingly gorgeous Get Carter theme.

Sarah Angliss
Spacedog UK

Technical how and why

I wanted some more technical details, so Sarah followed up with this explanation (thanks!):

I use pitch detection, plus classic old-school servo control, to make her work. Her theremin and mine (or my synth) are both connected to a Max/MSP patch running on a Mac. A phidget board interfaces her to the Mac. The patch is constantly measuring the error in her pitch. I use the error to control the velocity of her pitch arm servo – if the error is greater, it moves faster.
That’s why she’s constantly adjusting herself, as I play, to keep herself in tune. The very crude servo control gives her pitch a certain amount of portamento and overshoot that gives it that sloppy pitching that you get with a human player. I’ve added the little hairs of wire to the end of her egg whisk to give her some fine, Rockmoresque vibrato.

The biggest concerns were getting enough earthing and conducting area – I noticed Lev [Ranjit’s ‘bot] is made of metal which must be a huge help here.

Clara is earthed to my theremin and is packed with silver foil to make her a better conductor. She still needs a lot of work to improve her range and reliablility – but she’s just about good enough to get out of the box and play ‘live’ in my stage shows.