Washington National Opera's tuneful 'Little Prince' pleases kids -- or does it?

People like to go to live shows over the holidays, and they like to take children to them. The opera world would very much like to participate in this. Yet it comes up, time and again, against the question of what constitutes a "children's opera" -- which, much like "American opera," can be variously interpreted as being an opera for children, or involving them.