THERE ARE MANY WALK-ON PARTS in Shakespeare’s plays, especially those produced with a budget large enough to pay for the actors. Watching a production of Julius Caesar, I was distracted by a spear-carrier in the background.

He had no lines, and his only duty was to hold the spear and look like a guard. But he had clearly lost interest in the proceedings: he examined his fingernails, gazed sideways into the wings and up into the flies, and stared at his feet.

The moral of which, if there is one, is: if you’re on stage, you’re performing. An uninvolved extra in a Shakespeare play is as distracting and out of place as a digital watch.