I am a piano technician and was at a concert last evening when the
lady next to me asked me if I knew someone that could repair a music
box chair.  She had a picture of it on her iPhone and it was a chair
that had a music box mounted under the seat.  When you lift the hinged
seat you see the music box.

She is concerned that if she tries to wind the key it will break but
she would like to hear it play.  Does anyone know what this is called
and how it can be repaired?

James Kelly