The Metropolitan Museum of Art Centennial was celebrated with exhibitions, symposia, concerts, lectures, the reopening of refurbished galleries, special tours, social events, and other programming for eighteen months from October 1969 through the spring of 1971. The centennial's events (including an open house, Centennial Ball, year-long art history course for the public, and various educational programming and traveling exhibitions) and publications drew on support from prominent New Yorkers, artists, writers, composers, interior designers, and art historians. In 2009 Michael Gross published "The Secret History of the Moguls and the Money That Made the Metropolitan Museum, an unauthorized social history," and the museum bookstore declined to sell it.