In their introduction to the exhibition Bahia no Ibirapuera, at the 5th Sao Paulo Biennial (1959), architect Lina Bo Bardi and theater director Martim Gonçalves argued the ephemeral materials they used—in both the exhibition architecture and content—were a deliberate renunciation of “the undesired eternity of the work of art.” The exhibition had eucalyptus leaves covering the floor, and proudly displayed folkloric objects from the state of Bahia amidst compositions made from refuse materials. The result united the ephemeral qualities of experience to a political stance against a more elitist understanding of art. This position was a departure from Bo Bardi's work, until then characterized by alliances with Sao Paulo's ruling class in the production of a high modernism of industrial materials and strict geometries. Bo Bardi and Gonçalves were not alone in their turn towards ephemeral experiences. Only a few months before, the Neoconcretists, led by art critic Ferreira Gullar and influenced by the writings of Maurice Merleau-Ponty, had argued for the work of art as a sensorial experience, less machine-like and closer to the human body. These aesthetic discourses took place in the context of the accelerated industrialization of the country, fueled by the developmentalist policies of president Juscelino Kubitschek and materialized in the looming completion of Brasilia, the new capital. Kubitschek's policies modernized Brazil, but also increased inflation and wealth inequality, particularly in the countryside. In this context, Bo Bardi and Gonçalves argued for an ephemeral architecture more akin to theater, which would come from the non-privileged as opposed to the cultured elites. In this paper I trace these intellectual discourses and argue the exhibition was a key moment in which Bo Bardi shifted her understanding of architecture—from fixed, immutable object to a frame in the production of ephemeral, sensorial experiences.