What artists do you know of that have used a theremin live?
This is a theremin
I think it's an awesome, and very underrated instrument.
And here is Nine Inch Nails using one live
https://www.youtube.com/watch?v=qTJDMByDX18
And here's Placebo with one used live
https://www.youtube.com/watch?v=kK2fIb86fBI