Hartford’s Atheneum has seen a 27 percent drop in attendance in three years. It’s dropped an expensive building expansion and is embarking on an alternative plan. Changes in the museum’s focus are underway. “The idea that the Atheneum can do an important blockbuster show year in and year out is simply not true anymore. Those shows were, in my judgment, the product of an economy which no longer exists, and they are a product of a certain way of thinking about museums that I’m not so sure that in the end was productive.”