In some narratives, flashbacks are used not just to provide the many useful elements already mentioned above, but to also tie together a theme.
In James Baldwin's "Sonny's Blues," for instance, flashbacks certainly serve to provide the history of Sonny and his brother and their family who are gone. But, these flashbacks also contribute to the musicality of Baldwin's narrative composition. Moreover, they act as something like a leitmotif in a musical piece in order to unify the narrative with the theme and characters, whose lives are assimilated with the lives of their father and uncle before them. All the pain and suffering of the men in the family is channeled into this lietmotif of violence and music and pain. Indeed, meaning is revealed in the story's structure of which flashbacks act as recurring motifs (leitmotifs) of suffering and communion.
As Sonny plays at the nightclub in the last part of the story, the narrator/brother listens, and he experiences an epiphany:
Freedom lurked around us and i understood, at last, that he could help us to be free if we would listen, that he would never be free until we did.
In the music and the "leitmotifs," or recurring blues themes of Sonny's life, the brother hears the language of the soul that touches upon the flashbacks of the past and the agonies of the present--those "personal, private, vanishing evocations" of the man who creates the music and the one who listens, tied together by the past that is brought to life with flashbacks. And so, with this use of flashbacks and those memories carried by the music, the brothers rescue and redeem themselves.
When authors employ flashback as a literary device, they break with the traditional, chronological storytelling narrative. Therefore, when the flashback is included, it will likely bring information that had not been produced previously. There will be new details and facts that may help tie in the events taking place as part of the plot.
Flashbacks can be included as a break in the narrative, or blended within the story of the characters as it happens in the style known as "stream of consciousness". In this type of story, the narrator is the main character, and is in constant analysis of a situation speaking from his or her own point of view and using first person.
Flashbacks can also come as dreams and memories, thus manifesting to the main character subconsciously. Whichever way they occur, their purpose is to add information, clarify issues, and perhaps be the solution to the story's problem or main dilemma.
A flashback is a literary device in a story that provides some background information on events, situations, or a character's past history; author's often use flashbacks to reveal some important truth about a character's past that otherwise the reader might not have known. Flashbacks can be useful in terms of characterization but also plot development or conflict. For example, a flashback can reveal why some key event in the story has happened or why two characters struggle to get along with each other. In analyzing your specific story, ask yourself:
1) Does the flashback reveal something about one of the characters?
2) Does the flashback hint at an older conflict, rivalry, or injustice that could influence the current conflict in the story?
3) Does the flashback tell the reader some key piece of information necessary to understanding the development of the plot?
4) What effect does the flashback have on the chronology that is development in the story?