Pianist Lang Lang is much in demand these days, and like any soloist, his schedule generally demands that he flit from city to city, with barely enough time to accustom himself to the piano placed in front of him before it’s time to move on to the next one. And yet, there Lang was in Detroit this week, taking an entire day off to entertain 80 schoolchildren at a private home. “It’s difficult to convey how rare it is for a pianist of Lang’s celebrity to find his way to an anonymous suburban home to play a free concert disconnected from any corporate sponsorship or commercial agenda or the kinds of formalized outreach and education programs that have become de rigueur in classical music. Maybe Brad Pitt accepting an invitation to your daughter’s birthday party would be a similar jaw dropper.”