The relationship between artist and architect has a very long tradition, but it was in the 1930s that, in the United States and then Europe, the artistic work related to the architectural project and the public space became essential. In various countries, the idea of allocating a percentage of the cost of creating public buildings to artistic interventions was drafted into law. Despite the numerous significant works, the discipline of the “percent for art” has often supported traditional artistic expressions and has been repeatedly the object of criticism and redefinition. In the post-war period, experiments explored other forms of collaboration between artists and architects, embodied in quality works involving major figures in the history of art and architecture. Today, new methods are being experimented with in the public art sector, with the aim of involving different disciplinary fields and the citizens themselves.