Theremin-playing robot

Posted: 11/29/2010 2:34:27 AM

From: Kyoto, Japan

Joined: 11/29/2010

Not sure if this is the right forum to post in but here goes!

Theremin robot plays Greensleeves (

I'm trying to make this robot play the theremin less "robotically" and more expressively. As you can see from the video, it still has a long way to go. However, the most basic problem is pitch. Any suggestions or comments are welcome :)
Posted: 11/29/2010 6:26:16 AM

From: Canada

Joined: 8/1/2008

Many attempts have been made in the past to design a mechanical theremin player that plays with feeling and sensitivity. In fact, one of the earliest attempts (back in the 1990's) was made by the founder of the Theremin World website, Jason.

You have made a great start with HRP-2 but you have programmed him to do something that is considered a bad habit by most serious theremin players. He is "pumping". This is when a theremin player accompanies every note played by the pitch hand with a dip of the volume hand toward the volume antenna.

Players presumably do this in order to articulate notes clearly and suppress the inevitable slide between them. What they end up doing is disconnecting the notes. There are moments when this is an effective technique but it should not be done on every note because it destroys the natural "legato" (smooth and flowing) feel of the instrument.

The slide between notes can be minimized by lightning fast (and accurate) movement of the pitch hand.

If you need guidance as to how this can be accomplished by HRP-2, I suggest you contact Dr. Noonian Soong.
Posted: 11/29/2010 10:44:04 PM
Jeff S

From: N.E. Ohio

Joined: 2/14/2005

I think it amazing it can play that well. It certainly blows the chips out of any theremin playing robots we've seen so far. In fact, right now it plays as well as, if not better than, many real humans we've seen.

The slight wobble does add a little vibrato, although it is subtle and uncontrolled. As with humans, the lack of digital articulation (fingers) limits the fluidity and will increase the gliss (sliding) between notes.

Still, it's certainly an impressive effort.
Posted: 12/1/2010 1:06:54 AM

From: Eastleigh, Hampshire, U.K. ................................... Fred Mundell. ................................... Electronics Engineer. (Primarily Analogue) .. CV Synths 1974-1980 .. Theremin developer 2007 to present .. soon to be Developing / Trading as . ...................................

Joined: 12/7/2007

That is great!
Is the robot actually 'listening' to what it is playing, and adjusting to get the correct pitch, or have you actually programmed the position for each note?
.. If the latter, then your patience is astounding.. and it must be one hell of a task to set the robot up exactly as before, with theremin exactly as before, if one wants to repeat a performance, I would imagine..

To make it more like (most) human players, you need to program some special attributes into it..

1.) It must believe it plays accurately and expressively.

2.) It must not play accurately and expressively.


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