I’d heard the strains of Mozart’s Turkish March while passing the 14th Street – Union Square Station on the R train before, but it was only this past week that I discovered its source. A small boy, who looked like he wasn’t halfway through elementary school, was magically producing the music. Off to the side, a man with a wooden clapper stood, rhythmically tapping it against the metal posts to provide a live metronome. The performance was not brilliant and the mistakes were detectable even to my amateur ear, but it was definitely astounding and the young performer deserved all our applause and attention. However, the most interesting aspect was after he bowed in all directions, the man watching him came over to review the errors and fine tune the piece. His presentation was a work in progress, and we turned out to be spectators of a class, not a final concert; I hope to listen to the boy improve and perfect his art as I stop by.