This one surprised the hell out of me! I had a plastic desert bowl and a violin string so threw together a prototype to get them together.
I'm no violinist, I've managed some horrible squeaks and squeals on them before, but this was quite easy to get a good sound out of...
Try and guess the tune!
The 'bridge' is a nylon fishing line tied tight around the violin string and two small holes in the base of the bowl.