Classical tragedy preserves the unities -- one timespan, one setting, one story -- as they originated in the Greek theater. It also defines a tragic plot as one with a royal character losing, through his own pride, a mighty prize. Modern tragedy redefines the genre, with ordinary protagonists, realistic timelines and settings, and multiple plots.
Unified Classic Tragedy
According to Aristotle's Poetics, the tragic playwright must create a unified work. The play's running time must be the exact timespan of the tragedy, with no breaks or flashbacks; the setting must remain in one place. Most importantly, the action follows one inevitable course, and the tragic hero must be royal or highborn. In addition, this hero desires a greater good, such as the rescue or unification of his kingdom, and he places that prize at great risk with his own choices.
The Elements of a Tragic Fall
Aristotle further elaborates that the tragic hero must, by the play's end, lose everything he has gained through hubris -- blind pride that defies the gods. In Sophocles' Oedipal cycle, Oedipus tries to discover his birth secret, while Creon refuses honorable burial to Antigone's brother. Both heroes lose their kingdoms as a result. Shakespeare carries Greek-style hubris even further, as he has Macbeth lose his soul, Lear his sanity and Hamlet his conscious identity, before robbing each character of his life and kingdom as well.
A Critic Defines Modern Tragedy
Critic Pauline Kael, in reviewing the movie of Arthur Miller's "A View from the Bridge," gives an excellent definition of modern tragedy when she notes that a tragic hero "must have greater aspirations, ambitions ... what does Eddie Carbone [the Miller tragic hero] want? He wants his wife's niece." The modern tragedy is thus redefined: in modern tragedies, smaller men with smaller dreams act through impulse, rather than hubris. The unities are ignored -- Miller's work spans weeks, with subplots -- although the characters' ends are still tragic.
Modern Tragedy Adds Irony
Miller produced several modern tragedies about ordinary men with puny dreams and sorrowful finales; the most famous is "Death of a Salesman." Another contemporary example is David Mamet's "Glengarry Glen Ross," in which tragically small-minded salesmen fight over crooked sales jobs. Modern tragedy therefore adds irony to Aristotle's mix, reducing once-heroic tragic figures to the size of ordinary humanity.