Final answer:
Postmodernism in architecture, exemplified by Michael Graves and others, is marked by a playful eclecticism, historical pastiche, and the appropriation of different styles and ornaments. It embraces bricolage, collage, and blurs the boundaries between various cultural forms.
Step-by-step explanation:
Postmodernism in architecture is characterized by its departure from the modernist ethos of simplicity and the reintegration of ornamental and expressive features from various periods and styles. Architects like Michael Graves and others signified this shift with the introduction of playfulness and historical reference in their designs. Utilizing elements such as bricolage, collage, and appropriation, postmodern buildings often combine materials and styles eclectically, creating provocative and unexpected visual experiences. Johnson's Madison Avenue skyscraper's whimsical top, reminiscent of a Chippendale cabinet, contrasts modernist ideology, illustrating a characteristic postmodern move towards historical pastiche and layered meanings. Similarly, Frank Gehry imbued his creations with a sense of playfulness, also indicative of postmodern values. These approaches reflect the broader cultural postmodern tendency to challenge boundaries, blend media and styles, and repurpose historical motifs within contemporary contexts.