That story about the chairback sign doesn't make the point Jim would like it to.

Most showbiz performers would have seen it as something to riff on for an ad-lib routine. Imagine what Matt McGinn or Hamish Imlach could have done with it (in fact they'd probably both have been capable of putting the sign there themselves). They'd have had the audience in stitches over it with a routine nobody could have seen coming.

The fact that MacColl and Seeger couldn't come up with such a response says they weren't exactly A-list troupers.

And if we're looking at current performers: who are the great stage-repartee people now?