Now here is an astonishing piece of music criticism conceived and written not by a music critic at all but by the Washington Post's resident humorist Gene Weingarten. Who but a man who makes people laugh for a living would think of talking Joshua Bell into playing for quarters during rush hour at L'Enfant Plaza Metro station in Washington, D.C.? The question at hand: How many commuters, as they plodded their weary way past the virtuoso with the multimillion dollar fiddle, would recognize that they were hearing something special? How many would notice that there was a fiddler at all? And how much money would land in the Stradivarius' open case? I won't steal Weingarten's thunder by giving away the answers, but knowing them is just the beginning in an essay that ranges from Ellsworth Kelly (what if you hung one in a restaurant?) to Immanuel Kant (what is beauty, anyway?), surveillance, The Cure and the definition of personal space. But after I got to the end of the article, the main philosophical problem that continued to haunted me was, Why didn't I think of doing this story?