The Seagram building, a Manhattan skyscraper completed in 1958, has a modernist design. Like most classic modernist structures, it has no added or unnecessary ornamentation. The stark beauty of the design comes from elements necessary to the structure itself, such as the exposed steel beams that support it. Like many modernist structures, it is made of large areas of glass and does nothing to disguise its form. What you see is what the building is; there are no attempts to trick the eye.
In contrast, the early 1960s Vanna Venturi house—which was not built much later than the Seagram building—is an early example of post-modernist architecture that deliberately breaks away from modernist tradition. For example, the architect (Robert Venturi) added decorative elements to the facade that served no functional purpose but were instead included to add "whimsy." Furthermore, the building is designed to play tricks on the eye so that, from the front, the house looks much larger than it is. Also, unlike many modernist buildings, it uses limited amounts of glass.
Neither house, however, could be mistaken for traditional architecture. The Seagram building's soaring glass and steel design is anything but traditional, and the Vanna Venturi house's blocky and off-kilter look may not be modernist but nevertheless represents architecture that is new and experimental.