Building a lap steel theremin

Pardon my ignorance, but what is a ring controller?

I'll leave the explanation of a ring controller to someone who is more qualified.

I have never seen one. I've only read about them.

I think the ribbon controller would be ideal for this project. You could tune it with the strings and get a really cool sound.

If you are going to use an antenna you would have to raise it up high enough so that the strings would not interfere with it.

As far as vibrato, the strings vibrate much too fast to add anything we could hear.