We discovered a web-based tool that somewhat replicates the functionality and tone of a theremin.
A theremin is perhaps the most basic of electronic instruments and yet, in the right context, it can sound absolutely awesome.
If you go to the website via the link below, what you will find is definitely not a theremin, but it is a rather good attempt to make a playable instrument in a web browser, with the most minimal of interfaces.
What you have to do is click with your mouse in the yellow area, then move it around and hear the tone follow you. You can 'wobble' your finger on the trackpad to give quite a passable vibrato. I think there's a missed opportunity here, which is to use the vertical axis to modulate or modify the tone, but this is clearly just a proof of concept that isn't supposed to be taken seriously.
Having said that, it is definitely good fun for a few minutes.
And it definitely makes me want to get a real theremin.
http://femurdesign.com/theremin/
Graphic by Shutterstock