Today it looks classic, in much the same way that suchmasterpieces of midcentury modernism as, say, Mies van der Rohe's Seagram Building or Frank Lloyd Wright's Guggenheim long ago ceased to look "modern, " at least in the informal sense that most people have in mind when they use the word.
And you simply can not ignore the masterpieces preening in their gorgeous spaces suchas the Hirshhorn, east wing of the National Gallery, Corcoran and the Phillips Collection.