Ford breaking the Western conventions, categorized sound into diegetic and non-diegetic sound. He use neutral shot, a perspective from directly on axis line, continuity of screen direction maintained by the intense level of story action. Two characters who can't occupy roles within civilized society, prostitute, alcoholic doctor. Note doorway shot.
The very first modern western movie, and the model for all of those to come. The elements of narration and filmography that it sets hold steady until now and probably for still a long time - see Tarantino's hateful eight for their confirmation. Most of the ideas on it are simple, but it takes a master to put the ingredients all in place and to cook something this delicious. Without any obvious main character, but rather a complex mix of persona, each cristallizing a class or a segment of society. This a Western movie to be sure, with all the parts that make up the mechanics, but it is above all a satire. One that is politically engaged too, especially in regards to the banker role.