Helio Oiticica (1937-80) was one of the most brilliant Brazilian artists of the 1960s and 1970s. His unique melding of geometric abstraction with works that directly engage viewers' bodies has influenced contemporary artists from Gabriel Orozco and Cildo Meireles to Rirkrit Tiravanija and Nick Cave. This is the first book to examine Oiticica's impressive works against the backdrop of Brazil's dramatic postwar push for modernization. From Oiticica's late-'50s experiments with painting and color to his mid-'60s wearable Parangoles, Irene V. Small traces a series of artistic procedures that foreground his later inclusion of the spectator. Analyzing artworks and a wealth of archival material, she shows how Oiticica's work recast-in a sense "folded"-Brazil's utopian vision of progress and the legacy of European constructive art. Ultimately, Helio Oiticica argues that the effectiveness of Oiticica's participatory works stems not from a renunciation of art, but rather from their ability to dialogue with their surroundings and reimagine the traditional boundaries between art and life.