HELICOPPER

I'd just got home from singing at a local care home this afternoon when the police helicopter came and hovered over the house for several minutes. I don't think the two events were related.

The title is the punchline to a "what do you call..." joke which used to send the four-year-old daughter of a friend into paroxysms of squealing laughter many years ago (she must be about 50 by now). I can't remember the exact joke, but I'm sure you can supply something appropriate.