In an interesting experiment, the Washington Post's Gene Weingarten sent classical violinist Joshua Bell into the L'Enfant Metro station for an incognito street-performance. Weingarten's article on the result is well worth a read.

(And for more great long-form Weingarten, be sure to check out Doonesbury's War.)

Update: In the interest of fairness, it would appear that there are plenty of people who aren't quite as impressed as I am. To the extent that those people object to Weingarten's occasionally-purple prose ["Tall and handsome, he's got a Donny Osmond-like dose of the cutes, and, onstage, cute elides into hott."], they'll find no argument here. But to the extent that they attack the story's scientific bona fides and read into it a sanctimonious rant on the cultural cluelessness of Washington's Metro riders, I think their indignation is misplaced. To quote Weingarten's online chat:

[Generic Questioner]: Was this story intended to be an indictment of the soul of the federal bureaucrat?

Weingarten: The simple answer is, no. It was not my intent, nor could anyone reasonably draw that inference from the story. We didn't have a control group; we had only one shot at the experiment, and you just can't fairly generalize one way or another. I really believe this.