Good songs to play?

You've got to check out Peter Pringle's version of Pavanne by Fauvre on peterpringle.com. It's in the theremin download section of his website.

He uses a theremin double tracked to create harmonies - it's SO captivating, but slow and easy to play

best songs are the ones you can sing, if you can sing and understand the pitch changes it will be a million times either to play. a great way to practice is to hum and play together.