It's probably possible to overstate the importance of Bonnie and Clyde to the subsequent development of American cinema, but you'd have to indulge in some pretty outrageous hyperbole to do it. It almost single-handedly dragged Hollywood into the aggressive stylistic modernism that Europe had been enjoying for most of the 1960s; there had been scattered earlier efforts to incorporate the attitude of the French New Wave into an American movie (among them, in fact, was 1965's Mickey One, which shared Bonnie and Clyde's director, Arthur Penn, and lead actor, Warren Beatty), but none that had clicked in a big way with audiences and critics. It dragged Hollywood into a new, previously inconceivable place of frank sex and violence onscreen, putting the final nail in the coffin of the old Production Code. It dragged Hollywood into dealing with the fact that the best way to engage young people was to let other young people communicate to them on their level, telling a ruthlessly sardonic anti-establishment story whose period trappings don't even try to obscure the fact that it's really about the wholesale rejection of the "adult" regime that was responsible for getting the United States mired in a war in Vietnam. Hell, it even drew a clear line between two generations of film critics: Roger Ebert and Pauline Kael first made their names championing the film, while Bosley Crowther's heated hatred of the film was at least partially responsible for his firing from the New York Times.

None of which is obvious watching the film now, but that's largely because of its success: in 1967 Bonnie and Clyde, along with The Graduate, was arguably at the vanguard of what we now call "modern cinema", depending on you want to draw that line ("anything made since I was born" seems to be the most popular definition on the internet). The cultural impact of those two movies defined and continues to define everything that got made after them. And what hit like a ten-megaton bomb at the time the film was new has been so thoroughly absorbed by filmmakers in the generations to follow that Bonnie and Clyde merely looks normal now; Dede Allen's Godard-influenced editing that was perceived as visual savagery in '67 looks a bit genteel stacked up with just about any Cuisinart-cut summer action tentpole, and you can see worse things on network television than the violence that led moralists to speak against the film with a fervor you or I might reserve for a feature-length apologia for pedophilic cannibalism (even Jack Warner, whose namesake studio financed the movie, despised it so much that he attempted to bury it on the B-circuit, where it was discovered and passed around by dazzled young audiences, making it one of the truly legendary grassroots box office hits of all time). There's a little bit of Bonnie and Clyde in a great many American movies, whether in aesthetic, attitude, or just the freedom to show some blood.

The project was conceived by writers David Newman & Robert Benton in the hopes that they could put it in front of François Truffaut, who did end up giving some advice on how to shape the material (and yet, it bears a more obvious debt to Jean-Luc Godard's technique and narrative interests, at least as far as I can tell). So any resemblance to European filmmaking, and any tendency to say a loud "fuck you" to the Hollywood establishment is strictly intentional. The film's story is told in a highly elliptical way, collapsing the time frame of the events depicted (late in 1931, through 23 May, 1934) into a rush of disconnected events that could just as easily take place over a month as over a few years. Clyde Barrow (Beatty), an ex-convict who wants to be a bank robber, meets Bonnie Parker (Faye Dunaway) while trying to steal her mother's car; they flirt shamelessly and when he shares his dreams of criminality, she agrees on the spot. As they break the law across Texas, Oklahoma, Missouri, and Kansas, they pick up Clyde's brother Buck (Gene Hackman) and his wife Blanche (Estelle Parsons), as well as a socially awkward mechanic named C.W. Moss (Michael J. Pollard), to create a little ad hoc family for themselves. All while being celebrated by the dirt-poor farmers of the Depression-era and hunted by the cops of several states, embodied by humiliated Texas Ranger Frank Hamer (Denver Pyle). It's one of the most directly romantic pro-criminal films since the early sound years, when the classic gangster picture was at its height; and that mentality was every bit as profoundly important as the film's stylistic radicalism in endearing it to a generation of young folk for whom the movies were out-of-touch and unable to say real things about actual life.

In putting the story across, the writers and Penn went all-out in experimenting: with a fluid, more impressionistic than precisely descriptive scene structure, as mentioned; and with a wildly fluctuating range of tones, from genial comedy (this was the film debut of Gene Wilder, one of the greatest genial comedians the movies ever knew) to sarcastic cynicism; from sweat-soaked eroticism to sweet post-coital shyness; from picturesque nostalgia to fashion magazine cool; from thrilling action to brutal, distressing violence, punctuated and emphasised by the unpleasantly harsh bullet sound effects that Beatty insisted on cranking up louder than the rest of the soundtrack. It's certainly fair to say that this patchwork tonality was as deliberate as anything else in the film, a calculation to keep the movie unpredictable and energetic.

For energy is the most important element of Bonnie and Clyde: it has many things to say about society in 1967 and a handful of things to say about society in 1931, but mostly it has to say things about how cinema can be, when it's not pinioned by the stuffy solemnity of the big studio pictures, like the pious Guess Who's Coming to Dinner or the suffocating Doctor Dolittle, both of which were incongruously nominated for the Best Picture Oscar alongside Bonnie and Clyde (this is the point where I finally get to mention Mark Harris's glorious 2008 book Pictures at a Revolution, a study of the production of the five '67 Best Picture nominees and the culture that produced them; it's among the best general-readership film histories that I've ever read, and I recommend it to each and every one of you). It sounds like an insult, but it absolute isn't, that Bonnie and Clyde is a really surface-level film; not because it has no depth, but because what's happening on the surface is tremendously important. Dunaway and Beatty's performances, which irritated me the first couple of times I saw the film, are as much a series of poses as they are "acting", but that's entirely the point, of course: Bonnie and Clyde are seen here as a form of pop art rather than as human beings, with some shots of Dunaway especially that frame her with exactly the same dramatic intensity as a comic book panel or Lichtenstein painting. It's a movie about visual iconicism: on the narrative level, we see this in the repetition of the Barrow gang sending their own photographs and poems to the newspapers, to craft their own image (this includes recreating a famous picture of the real-life Parker with her leg on a running board and a cigar chomped between her teeth); it crops up in Theodora Van Runkle's costuming, which is far more self-consciously stylish than makes even a little bit of sense for a Depression-set crime drama; it's at the heart of the cinematography, a point of contention between Penn and DP Burnett Guffey, who didn't understand what the director was getting at. But the flatness and overly-yellowed color balance gives the film the feeling of a series of moving pictures from a photo album, deliberately artificial in its attempt to mimic natural weathering, hyper-modern in its aping of and old-fashioned look.

Radical, challenging movies have always existed; Bonnie and Clyde was lucky to have the exact right mix of onscreen talent and offscreen social upheaval to explode in the Zeitgeist in a way that the weirder, harder Mickey One had no chance to (it's also mostly an artistic leap forward in an American context; Godard's Week End came out the same year, in comparison to which Bonnie and Clyde looks boringly conventional). And if this film hadn't filled the niche it did, something else would have come along, surely. But the point is that Bonnie and Clyde did end up filling that niche: it got to be the movie to aggressively, showily re-define the kind of stories that Hollywood movies could tell and the way that they could be told through daring cinematic language. I don't know if the film's inherent quality is quite as impressive as its seismic effect on the medium's possibilities - I frankly like a lot of the movies that picked up its baton and ran with it in the years to come quite a lot more, and The Graduate strikes me as the more consistent and effective movie qua movies - but after nearly a half century, the film's influence is still overwhelming and obvious, and that kind of legacy is impossible to deny or diminish in any way.

Elsewhere in American cinema in 1967
-Paul Newman and Strother Martin have failure t' communicate in Cool Hand Luke
-Audrey Hepburn plays a blind woman in the classy horror-thriller Wait Until Dark, directed by James Bond specialist Terence Young
-D.A. Pennebaker's radical Dont Look Back, a Bob Dylan documentary, opens

Elsewhere in world cinema in 1967
-In Sweden, a country that had long been known for its saucy films, Vilgot Sjöman's I Am Curious (Yellow) still manages to incite controversy for its sexual content and aggressive style
-Sergei Bondarchuck completes his massive four-part adaptation of War and Peace in the Soviet Union
-Suzuki Seijun's defiantly bizarre crime thriller Branded to Kill gets him fired from Japan's Nikkatsu