This is what I usually do this time of night," Prince said at one point. "It's better with you all present." A genius, at home, alone at the piano, performing to maybe a little more than a thousand fans — it was unmistakably a once-in-a-lifetime event. Of course, there was a second show an hour later. Because Prince is the kind of guy who makes once-in-a-lifetime events happen twice in the same night.