It has been somewhat more difficult than I originally thought, coming up with a definition for noir. It seems to have been something which has eluded critics and thinkers alike. Although, I'd venture the chief point has been their inability to find a definition that works for everyone.
But, here goes my attempt: noir, first off, refers merely to the film genre, not really the literature. Of course, at no time in my research did I come across any mention of theatre delving into the Noiric arts. The movement (or style (as Thomas Schatz would have you) or genre or what-have-you(Alain Silver refers to Noir as a cycle, or a phenomena, that the noir mood was a period with relative geographic and temporal boundaries)) began in the United States as a literary art form known as Hardboiled, which would also become known, later, as Pulp, due to the cheap printing that normally accompanied it. This was the world of Dashiell Hammett and Raymond Chandler, and was typified by generally dark themes particularly those which emphasize moral ambiguity and sexual motivation. There seems to be a need in the noir for an unsentimental portrayal of sex violence and crime.
The Hardboiled fiction of the thirties gave birth to the "Classic" (and to some, only) period of noir films, from late thirties through the late fifties. Certain critics have argued that all Noir films following that period have only been as homage or allusion, and not qualifiable as Noir. I happen to argue that is hogwash.
Okay, enough of the history, you say, what makes up Noir? At one point in my reading, five words were tossed out as elements of noir (though written directly after was the phrase that most noirs have even some of these elements, and rarely all five... So why?... Anyway) oneiric, strange, erotic, ambivalent, and cruel. I didn't know what oneiric meant, and it means pertaining to dreams. The stereotypical notion of Noir seems to entail the protagonist being a Private Eye, a gumshoe, but the reality isn't quite true. Sure, Hammett and Chandler relied on the character as a private eye, but Cain (a later writer) relied on a less heroic lead with more emphasis on psychological exposition rather than crime solving. Indeed, most film noir was more likely to have a lead as a victim, or a person directly connected to the crime or problem in question.
So, Noir might not have a detective lead, but there's a crime? Well, mostly, but as stated above, there was a movement away from crime solving investigations toward psychological exposition.
But they happened in the gritty cities? No. Some did, but plenty happened in small semi-rural areas.
There is generally, and it would seem with Noir it is all general, there is a visual intricacy (principally derived from German expressionist film) and a complex voiceover driven narrative. They are sophisticated and bleak dramas (except when they're comedies) dusted with mistrust and cynicism, topped off with a generous helping of the absurd.
Noir's roots are in German Expressionism, French Poetic Realism and Italian Neo-Realism. I really don't know a heap about any of those, but I will certainly do a bit of peeking to see what is up, and push it onto here in the next few days.
Okay, so after reading this, did I figure out a definition of Noir? Not really. For me, noir deals with crime and betrayal and moral ambiguity, where people try to be Good in the face of a choice that isn't simple. The kill one to save five dilemma. But there's a sense of not taking prisoners, of actively seeking revenge when betrayed, of hitting back, at all times. Of using any and all means to win, and of having to accept different definitions to win...
Maybe I can just do as the Supreme Court has done before me... I can't define it, but I know it when I see it.
All of this, and the question remains: what the heckfire does this have to do with theatre? Well, can we translate this art form to the stage, or is it relegated to film and literature? That topic, my fine feathered friends, I think I will tackle later this week. Following German Expressionism, Italian neorealism and French PoeticRealism. Good day. Write well.