Sociology of film
The sociology of film can be clearly seen within the spanning genres of film since the creation of film. The genres span from Gangster films to Musicals that all have sociological aspects embedded in the course of the films. Every screenwriter has always tried to figure out what sociological aspects should be incorporated in a film so that they can reach out to a wide audience within the two hours in which their film is presented. "One problem, though, is that if the audience is the measure all things, then art becomes a reflection of sociology and dissecting audience tastes becomes the art."
"Somehow, although our poets have not yet defined it for us, a corporation lives a life and finds a fate outside the lives and fates of its human constituents."  The sociology of a film is created off of people and their situations that comes to a screen writer who then decides to make the film into a motion picture with the use of those actors and actresses that become the famous socialites of the film.
Since the creation of film, there are six main genres that comprise the film industry. These six genres are: Gangster, Hard Boiled Detective, Western, Screwball Comedy, The Musical and The Family Melodrama.
The Western tends to be about heroes riding their horses off into the sunset mountains after saving a town from the bad fellas coming from other towns. "The Western hero, in his physical allegiance to the environment and his moral commitment to civilization, embodies this ambiguity." 
The hero of the story is the protector of all men and women in the town, but he is also viewed as the symbol of Westernization within the United States. The town in Westerns also typically stands for the development of the west and the prospective future of striking Gold and other goods the Western World was said to have.
Gangster films show the side of hidden society that in the early twentieth century was swept under a carpet and not acknowledged. A lot of gangster films were based on true stories in which describe how the gangster world worked together within the organization and how they bought out quite a few police officers to be on their side in order to keep their profits coming in and their executions unknown or un-investigated. Example: Goodfellas
Later on the National Board of Censorship that was created in 1908 limited what could be shown in gangster films for fear of what people would get ideas for within the present society.
Hard-boiled detective films
Many popular films that are considered hard-boiled detective films have what is known in the film industry as film noir.
Film noir is a term that was coined by the French who categorized the films of the 1940s-1950s. "Generally speaking, film noir ("black films") refers to two interrelated aspects: visually, these films were darker and compositionally more abstract than most Hollywood films; thematically, they were considerably more pessimistic and brutal in their presentation of contemporary American life." 
The sociology of the hard boiled detective films seems to make American life seem violent and secretive.
In one of the most well known hard boiled detective and film noir films, Chinatown, society itself is brought to question with a large water scandal. The film deals with Sociological aspects of the scandal and those involved. The investigation of the detective begins as an investigation that "uncovers secrets under many layers, facades, red herrings, and networks of corruption, conspiracy and deception." 
Within this story of secrets and deception is one women who creates another aspect of the sociology of a film, a woman referred to in the film noir genre as femme fatale, a woman who is a dark, secretive, lead character that traps men and brings them into her web.
Musicals tend to show an inside view of Hollywood and the production of a show making musicals self-reflexive.
As seen in Singin' in the Rain, Gene Kelly plays a man who works his way up from a musician to the lead in a Hollywood film, thus showing social mobilization within Hollywood during the early stages of films. In Singing in the Rain, the cast is filming a movie in which is boo-ed before it is even released to the public because the challenge of the film's director is to switch the cast from non-verbal communication films to verbal, "talkie" films.
Musicals are more about the sociology of Hollywood and the happenings behind closed doors. The typical molded Musical also ends with the community coming together along with the musical leads finding love.
After the early 1980s, Musicals seem to disappear. In recent years, Musicals have begun to reappear in theaters and on television.
Screwball comedy films
Film critics believe that screwball comedies began with the movie It Happened One Night where an upper class soon to be bride and a lower class newspaper writer travel together and exchange satirical dialogs. This film lead the way for many other screwball comedies to be written. In "restructuring the fast-paced upper-crust romance, the screwball comedy dominated Depression-era screen comedy and provided that period's most significant and engaging social commentary." 
The social commentary in many of the screwball comedy films are that there is social mobility within America at the time. In It Happened One Night and Bringing up Baby both females leads are of high social status and fall in love with males of lower social economic status then themselves. Most screwball comedies also contain a lot of sexual innuendos that creates a movie containing quite a bit of talk of sex without actually any sex in the film. In screwball comedies, both male and female leads typically end up happy in their post-depression-era society together.
The family melodrama
The sociology of film seen in the family melodrama is that of the view of the American Nuclear Family.
"The focus of film melodrama of 1950s Hollywood is the bourgeois family and that it is distinguished by a strong sense of ideological contradiction reflecting wider uncertainties, fears, and neuroses prevalent in postwar Eisenhower America." 
These films use the technique of using music behind a scene, instead of like a musical with people singing to entertain. Using the music behind a scene creates emotion of the song and sets a mood for the scene itself. As reiterated by Thomas Schatz, "the melodrama's narrative formula-- its interrelated family of characters, its repressive small-town milieu, and its preoccupation with America's sociosexual mores-managed to live beyond the Eisenhower years and into the era of civil rights, Vietnam, the sexual revolution, and the Women's Movement." 
- Edward Rothstein. Is the Audience Being Rowdy?. New York Times. New York, N.Y.: May 27, 2000. pg. B.11f
- Tino Balio, The American Film Industry. The Fortune. 1976. Pg. 263.
- Thomas Schatz, Hollywood Genres. Random House. 1981.
- Thomas Schatz. The Western. Hollywood Genres. Random House, 1981. Pg. 51
- Thomas Schatz. Hollywood Genres. Random House, 1981.
- Tim Dirks. Chinatown. http://www.filmsite.org/chin.html.
- Thomas Schatz. The Screwball Comedy. Hollywood Genres. Random House, 1981. Pg. 151.
- Melodrama. http://www.filmreference.com/encyclopedia/Independent-Film-Road-Movies/Melodrama-MELODRAMA-AND-FILM-STUDIES.html
- Thomas Schatz. The Family Melodrama. Hollywood Genres. Random House, 1981. Pg. 224.