A onetime child prodigy, at 39 Joshua Bell has arrived as an internationally acclaimed virtuoso. Three days before he appeared at the Metro station, Bell had filled the house at Boston's stately Symphony Hall, where merely pretty good seats went for $100. Two weeks later, at the Music Center at Strathmore, in North Bethesda, he would play to a standing-room-only audience so respectful of his artistry that they stifled their coughs until the silence between movements. But on that Friday in January, Joshua Bell was just another mendicant, competing for the attention of busy people on their way to work.

The Washington Post sets up a unique social experiment - get a famous classical musician to play in a subway station and then see what the reaction is.  Includes video clips. 
(via Reddit)