The Heart Is a Lonely Hunter: linked stories or a novel?

Carson McCullers's The Heart Is a Lonely Hunter is a novel composed of what could stand alone as short stories, but unlike so many such novels it doesn't feel like "linked stories" but like a fully developed narrative. In other words, McCullers is able both to create a series of narrative arcs that cohere to form the grand narrative arc of this novel. How? The chapters themselves are each like a narrative about one of the people in the small Georgia mill town, but the chapters together constitute a narrative about the town itself - much more so than, say, Winesburg, Ohio, in which the town comprises a series of individual narratives but does not have narrative life of its own. Among the great chapters in section 2 of McCullers's novel are the "promming" chapter - Mick Taylor, now a 13-year-old in the Vocational High School (I for one was surprised that she is that old) who doesn't feel she quite fits in w/ any of the social sets invites about 20 classmates over for a "prom" party - which seems to mean that they take turns walking with one another up and down a the block, as in "promenading" I think; predictably, the party turns out somewhat disastrous - but Mick does get a chance to prom with her next-door-neighbor, a Jewish boy - leading to some strange scenes later in which Mick gives him a Hitler salute that he does not find to be funny in the least - one of the moments that places this novel in time. The other great chapter is Bubber's accidental shooting of the young neighbor Baby: in a panic after he shoots her w/ a shotgun or maybe a BB gun he runs away; Mick finds him and, to teach him a lesson, tells him he's killed the girl and the police are seeking him. Mick's not as smart as she thinks she is; rather than put the fear of God in her brother, this sends him into a real panic and he runs away. Anything could have happened, but they do track him down and bring him home - but as we see in later chapters, he's never the same child again, he's morose and angry. Other chapters in section 2 concern Doctor Copeland and his leftist advocacy and commitment to the black community, the death of Biff's wife, Alice, and Blount's continued attempts to be a leftist organizer, though he's continuously unhinged by his drinking - and always present is Mr. Singer, the man who is mute, and who draws everyone's story out, as he is the serene and sympathetic, nonjudgmental listener.