On May 17th, a black-tie audience at the Metropolitan Opera House applauded as a tall, jovial-looking billionaire took the stage. It was the seventieth annual spring gala of American Ballet Theatre, and David H. Koch was being celebrated for his generosity as a member of the board of trustees; he had recently donated $2.5 million toward the company’s upcoming season, and had given many millions before that. Koch received an award while flanked by two of the gala’s co-chairs, Blaine Trump, in a peach-colored gown, and Caroline Kennedy Schlossberg, in emerald green. Kennedy’s mother, Jacqueline Kennedy Onassis, had been a patron of the ballet and, coincidentally, the previous owner of a Fifth Avenue apartment that Koch had bought, in 1995, and then sold, eleven years later, for thirty-two million dollars, having found it too small.