In the last forty years or so, authorities across the globe have appealed to the notion of decorum to justify authoritarian policies of urban control. Such a notion is distinctly aesthetic insofar as it deals with good taste in matters of appearances and behavior; decorum is about what we should or is appropriate to see and do in public spaces. When considering how deeply discussions and policies of decorum shape our daily lives, it is surprising that aestheticians have largely ignored the city as a subject of inquiry. In this paper, I examine the heretofore largely overlooked link between the city’s decorum, as a key notion in political discourse, and the discipline of aesthetics. At a general level, I show that the urban landscape is a domain where politics and aesthetics merge. More specifically, I argue that street art should be conceptualized as a subversive response to the authoritarian aesthetics that is embedded in political discourse about decorum. Street art injects into the urban landscape a dose of spontaneity. In doing so, it turns upside-down the exclusionary strictures of dominant politics of decorum that admits as appropriate, and perhaps beautiful, only the authorized and the sanctioned. By creating temporary zones of spontaneity, street artists invite us to imagine alternative ways to use the city.