And now for something that has withstood the test of time...
When I first heard the Hallelujah Chorus, the audience rose to its feet, in keeping with a tradition that purportedly began with England's King George II in the 18th century. (When the monarch stood, everyone had to stand.)
The custom of rising when the Hallelujah Chorus is played may no longer be widely known or followed. But it may be that the food court audience was just startled by the unannounced performance. And surely it would have been awkward to set aside the nachos, hot dogs, and sodas and rise smoothly from one's plastic chair.
The contemporary audience wasn't impolite; in fact it applauded loudly at the end. Few at the shopping center may have heard of King George, but he was likewise a stranger to shopping malls and flash mobs. What we and he all felt in common was the surge of emotion when the chorus belted out "King of Kings" and "Lord of Lords" in Handel's many-parted composition. Hallelujah, indeed.