Old Comedy
Comedy (komedia) was introduced into the Greater Dionysia in 486 B.C.E., and the era of Old Comedy (the genre whose characteristics I will discuss below) is commonly held to end around the time Aristophanes's last play was staged in 388 B.C.E. Of the more than 600 comedies that were performed over the course of the century, only Aristophanes's have survived (and of those, only 11 are extant).

Comedy was an integral part of democratic Athenian life (which is perhaps why it drew to a close soon after the end of democracy in Athens). It had its roots in the tradition of "carnival"—that is, a time of year when the ordinary social hierarchy was turned upside down (thus, groups that were excluded from the demos, such as women, gypsies and slaves, acceded to a kind of faux power) and ordinary rules were suspended, allowing for the lampooning of august figures and sacred institutions. This suspension of everyday law was in itself a sacred ritual.

When the social ritual migrated to the stage, the form of drama we know as comedy was born. An intermediate stage, called komos, involved interplay between a rowdy group of revellers (the komos), drawn from the unenfranchised groups mentioned above and devoted to poking fun at (critiquing, challenging) prevailing mores; and a rival group called the antikomos, whose job was to persetute the komos. When lead actors (protagonist, antagonist, tritagonist) were added, komedia was born.

Old Comedy plays fell into three main categories: the mythological burlesque, the domestic comedy (cf. the modern sitcom), and the political satire (the category into which all the surviving examples fall). The latter generally presented the political underdog in a sympathetic light, offered unsavoury or grotesque portraits of contemporary leaders, and offered a resolution in which the bad guys saw the light, made peace with the good guys, and Athens was restored to her Periclean glory. The comic chorus initally represented a distinct, solidary group (like the old komos), but gradually lost this identity to merge its perspective with that of the audience.

Certain principles were not overturned in the "safe space" of comedy:
--one still didn't speak ill of the dead
--one did not undermine religion in ways that might linger after the play was over
--one did not criticize the institution of democracy
--one did not impugn the honour of any respectable woman.

A comparison of tragedy and comedy yields the following important contrasts:

Tragedy	Comedy
mythic, heroic	human, burlesque
never dealt with the "here and now"	often dealt with the "here and now"
stylized, archaic	more "spontaneous," popular, contemporary
high diction	low diction
masks, costumes conceal the private and particular behind the general and abstract	masks, costumes "expose" private parts (exaggerated phalloi etc.); emphasize the particular/ idiosyncratic (caricature masks)
theme: the fall of great men	theme: the rise of the "little guy" (traditionally unenfranchised groups)

In many ways, then, comedy "turns tragedy upside-down."

Structure
The typical comedy was structured as follows:
  --Prologue (introduces situation)
  --Parados (entry of chorus)
  --Agon (struggle/dispute)
  --Parabasis (direct appeal to the audience: in Aristophanes, usually dealing with the playwright's own views on the status of comedy)
  --five Episodes (scenes dealing with the comic theme)
  --Exodus (exit of chorus)

Frogs, specifically...
The Frogs is unusual because it received two productions (usually, a comedy was produced only once in Athens itself, since comedy tends to date pretty quickly [why?]): in 405 and 404 B.C.E. It's thought this play was re-staged in part because of its unusual parabasis, offering political advice--exceptionally, not in Aristophanes's own "voice," but that of the Chorus of Eleusinian Initiates (i.e., representatives of a divine mystery).

You know a lot about the political backdrop to this play from reading Thucydides. Frogs was written in 405 B.C.E., ten years after the disastrous Sicily expedition, and a year before the final defeat of Athens by Sparta (and replacement of democracy with oligarchy). All Athenian citizens are confined within the city, while Spartan troops harrass the remainder of Attica. Athenian naval power is also under threat from a rejuvenated Persia. Athens has just achieved a major naval victory at Argenusai, but at a hefty cost in men and ships. Slaves are being mobilized, with the promise of citizenship, to fight for Athens; but many "true-born" citizens oppose this policy, saying that Athens should take back its own (exiled) citizens first. The figure of Alcibiades looms behind these debates, since many people feel heis the only man who can save Athens. Alcibiades is in voluntary exile at this point, with charges of sacrilege against him for, among other things, allegedly defacing the Herms. There is a power crisis in Persia, which fuels Athenian hopes that Persia will withdraw its military support to Sparta. Cleophon (who will be sentenced to death in 404) has allegedly just turned down Sparta's offer of a peace treaty.

After the short-lived Oligarchic Coup of 411, in which an oligarchy of 400 temporarily suspended Athens's radical democracy, popular sentiment was all for punishing the oligarchs. The Chorus of Eleusinian Initiates proposes that, instead, the city forgive and reinstate the citizens who staged the coup, because the most educated people are needed to run the state.

Shortly after this play was staged, Cleophon was put to death and the would-be oligarchs were re-enfranchised. Whether or not the Frogs had a hand in determining these events is unclear...

The Plot (and related study questions)
One of the things a comedian was judged on was his ability to do new things with an old plot. Many comedies used the device of sending a character down to the Underworld to retrieve a deceased hero; here, the twist is in Aristophanes's decision (a) to send for two canonical tragedians (NB: Sophocles was not -quite- dead when this play was written, though he may have died before it was staged. Euripides would have been newly dead); and (b) to make a contest of it. What do you make of Aristophanes's choice to resurrect these two tragedians? How do you read his implicit critique of tragedy in particular and drama in general? And What do you make of the contest—is it fair? Who wins? Do you agree with the winner? What do you think Aristophanes thinks?

Comic Dionysus, too, was a popular fixture in comedy, along with Comic Herakles; both were generally portrayed as ludicrously fat and short of breath. All the gods (even Zeus!) were fair game for comic portrayal, but Dionysus lent himself particularly to the genre, as the god of theatre (and of misrule!). Here, too, we can imagine that Aristophanes is in dialogue with Euripides's Bacchae (406 B.C.E.). It's interesting to compare Aristophanes's Dionysus with Euripides's, since the two are almost exactly contemporaneous. What can you glean from the comparison?

The other notable aspect of Frogs in particular is the way the play seems to pivot on the parabasis; if we divide the play into two parts, one before the parabasis and one after, we see that the two parts are radically different from one another in tone, chorus personnel, and focus. What do you make of these shifts? What is the relationship between the two parts and what is each of them "doing there"?