A TV commentator said the other day that with all that was going on in the world today, President Obama had to “keep a lot of plates spinning.” Those of us who stayed home every Sunday night to watch Ed Sullivan knew exactly what he meant. But would anyone under 40 get it? What would plate spinning mean to today’s college freshman?

Ed Sullivan was the great divide between generations. If you watched Ed Sullivan to see the acrobats, the Borscht Belt comedians and the tiny little dogs jump through their trainer’s hoops, you’re from one generation. If you suffered through all that to see the rock band he had on that week, you’re from another. If you’re googling Ed Sullivan right now on your iPhone, well, never mind.

There was a time when, if you could imitate Ed’s pinched voice and self-hugging arms at parties, you could say almost anything and get a laugh as long as you said the words “Right here, on our stage tonight” first.