To start this discussion I am going to compare the definition of ‘genre’ and ‘style’:
Genre: categorizes films according to their similar storylines and obvious features. Eg: Western, Horror, Fantasy.
Style: categorizes the techniques used by filmakers and the way they choose to treat their work.
“A film style is a recognizable group of conventions used by filmmakers to add visual appeal, meaning, or depth to their work. It can encompass every aspect of film; dialogue, cinematography, attitude (i.e., seriousness or lack thereof).
Film style is distinct from film genre, which defines what a film is about – - Western films are about the American West, love stories are about love, and so on. Although some styles are strongly associated with certain genres, a style can be applied to any genre”
Arguments: is film noir a style or genre?
“Strictly speaking, film noir is not a genre, but rather the mood, style, point-of-view, or tone of a film. It is also helpful to realize that ‘film noir’ usually refers to a distinct historical period of film history – the decade of film-making after World War II, similar to the German Expressionism or the French New Wave periods. However, it was labeled as such only after the classic period – early noir film-makers didn’t even use the film designation (as they would the labels “western” or “musical”), and were not conscious that their films would be labeled noirs.” - http://www.filmsite.org/filmnoir.html
“Film noir has been said that it is and cannot be a genre because it is defined by mood and tone, it did not start out with a set of criteria to which any one filmmaker used to mould a film noir it came out of an historical context (Krutnik 16). It was coined by the French after they began to notice a certain similarity to American films after the war, they were foreboding, they consisted of shadows and pessimism, they dealt with thugs, dirty cops and nasty females (Krutnik 16 and 22). Film Noir was an unsystematic categorization of films made during or after World War II and had, in conjunction, certain narrative and thematic conventions (Krutnik 20). However if you were to look during our present day one could more or less say that film noir has become a genre. There are many films that set out to be ‘Film Noirs‘, take Sin City (2005). Sin City is a film that has both the semantic and syntactic approaches of film noir. It was done on purpose and made with conscious decisions as to the way the narrative and visuals would feel and relate to one another. To say that film noir is not a genre would only be telling of it’s origins, if it is at all possible given the definition of genre that a style can thus grow into a genre because of historical contributions and the aid of time than no other group of films is deserving more than the films of Film Noir (Bregent-Heald 136).” - http://mubi.com/lists/film-noir-as-genre-problems-and-approaches
“Typical, more conventional genres are characterized by character and conflict whereas film noir is characterized by its tone and mood. It seems that the content required for a film to be considered noir is too” - http://www.resnet.trinity.edu/wmclean/filmnoir.htm
“What complicates the identification of noir as a genre is the fact that noir emerged from multiple layers of already identifiable genres, like the gangster film, the melodrama and the hard-boiled detective film. As a result, noir initially was identified as a movement or style rather than of genre. Over time, this debate has continued, complicating the understanding of film noir and even further, the understanding of film noir revisionism.” - http://www.girlsaresmarter.com/laura/papers/Genre.html
“If you think movies are defined by their themes, then you probably think of noir as a genre. If you define films by their visual look and tone, then to you noiris definitely a style.” - http://www.greencine.com/static/primers/noir.jsp
“French for “black film” or “dark film”, film noir is a term used describe a genre of film popular in America between 1940 and 1960. Strictly speaking this is not a genre but a description of the film’s style and mood.
Film noir generally refers to the period between 1940 and 1960. Films made since then are sometimes referred to as film noir but some purists do not consider this appropriate. Recent films made in the style of film noir may be referred to as neo-noir or post-noir.
Film noir typically employs dark mood lighting, shadowy images, seedy locations, and crime/thriller plots with unhappy endings.
Corruption is a common theme, especially the downward moral slide of the anti-hero. Greed and sex feature frequently.
Film noir centres around unpleasant or destructive human emotion and behaviour. Protagonists experience feelings such as disillusionment, melancholy, hopelessness, pessimism, moral confusion, guilt, desperation, etc.” - http://www.mediacollege.com/misc/genre/film-noir.html
After reading all these arguments, I now believe that film noir is a film style, not genre, hence film noirs are characterized by their mood.