Ambient media are oriented towards tinting the space around them with a particular mood or emotional tone, which their users can then attune to. The dissertation begins by tracing how this use of media as a mood regulator emerges in postindustrial Japan, drawing from the longer histories of background music, environmental art, and therapy culture. What follows theorizes this aesthetics of atmosphere as found in music, animation, literature, and video art.The analysis explores the relationship between ambient media and landscape, dreams, the cosmos, domesticity and gender, the rhythms of urban life, cosubjectivity, and information overload. In each case, discussion focuses on how the aesthetics of atmosphere reimagines subjectivity vis-à-vis the surrounding environment, shifting the postindustrial self away from a social identity based in interpersonal relations and towards a more abstract sensing body developed with and through the moods afforded by mediated space.The central concern here is how the aesthetics of ambient media serve to erase other people from the sensible horizons of postindustrial life, while at the same time expanding the environmental affordances of the human body in new directions. The dissertation theorizes the dynamics of ambient subjectivity to reveal how the aesthetics of atmosphere are both radical and regressive, offering an aesthetic solution to the coexistence of diverse objects in space, yet at the same time denying the possibility of any direct encounter with difference.