Abstract: The article considers the peculiarities of the content of the Makrokosmos III series by American avant-garde composer George Crumb. The author reveals its semantic properties, the peculiarities of correlation between the image and the form; substantiates flagship epigraphs and draws parallels with other opuses of the composer. The author emphasizes that the image of Space, used by Crumps as a background, is revealed logically enough both of the level of content and of the musical language. The main object of the study - Makrokosmos III - is devoted to contemplating the outer nature of Space, thence comes the title - Music for a summer evening. Space for Crumb is a ubiquitous phenomenon existing at all levels of entity. It is considered as the world as a whole - everything around us. Space is understood not only as outer space with different objects which can be thought of as an unseen reality (owing to scientific discoveries, now we can judge about its structure and spheres), and as a perceptible reality (Space which is perceptible to the human’s eye), but also as a particular human’s life.