Scoring the largest public subsidy in art history was no easy feat. When the notorious Christo and Jeanne-Claude erected more than 7,500 orange fabric gates in Central Park, the most amazing aspect wasn’t the installation itself—it was the legwork that went into it. The artists spent a quarter of a century trying to cajole public officials to grant them permission to do the absurd in such a prominent forum. Their efforts are now the subject of an HBO documentary, The Gates. Filmmakers Antonio Ferrera, Albert Maysles, David Maysles, and Matthew Prinzing recorded the whole shebang, starting when Christo and Jeanne-Claude did—that is, in the ’70s at City Hall—and following the piece through its February fruition three years ago. The film shows at 5 p.m. at the National Gallery of Art’s East Building Auditorium, 4th St. & Constitution Ave. NW. Free. (202) 737-4215.