I find it easy to divide the films I have seen into commercial and not.
Commercial movies: Dead Poets Society, Educating Rita, Indiana Jones, Rain Man, Gorillas in the Mist, A Fish Called Wanda, Thelma and Louise, My Left Foot, Smoke, Hillary and Jacky, Gladiator.
It goes without saying that the Bond, Rambo, Police Academy, and Star Wars productions are commercial as anything.
Art movies: Jesus of Montreal, Siddhartha, Stormy Monday, A World Apart, Sugar Baby, Bagdad Cafe, The Navigator, The Unbearable Lightness of Being, 2001, Sex Lies and Videotape, House of Games, Salaam Bombay!, Angry Harvest, Fanny and Alexander, Breaking the Waves, The Vanishing, Secrets and Lies.
Having seen "The Music Box", a typical commercial movie, my ideas have clarified a little.
This film is schematic and linear. Overall it is predictable, though there are plot surprises, as in any thriller or court-room drama. It is the story of a woman who discovers that her father had been a brutal concentration camp guard.
It does not venture beneath the surface eg to give the father's side of the story. It never gives us a hint of why a seemingly normal man could commit such crimes. We are left with the comfortable conclusion that some people are monsters and others aren't, and never the twain shall meet.
There is no 'cutting edge', no feeling of the rawness, roughness, ambivalence and complexity that characterise life itself. Though all the action is credible or believable, the overall effect is not life-like. Films with the cutting edge make me think, "Yes, life is like that." By contrast, I found "The Music Box" corny.
Though Hollywood movies may be more sophisticated than their Indian counterparts, Sudhir Kakar's comments about Hindi films are relevant:
... the oversimplification of situations and the elimination of detail, unless the detail is absolutely essential. The characters of the film are always typical, never unique, and without the unnerving complexity of real people. The Hero and the Villain, the Heroine and Her Best Friend, the Loving Father and the Cruel Stepmother, are never ambivalent, never the mixed ticket we all are in real life... The intention is to appeal to the child within us, to arouse quick sympathies and antipathies, and thus encourage the identifications that help us to savour our fantasies more keenly.
Above all, the characters in "The Music Box" are plastic and one-dimensional, with minimal characterisation. All the people are there only to carry the plot. They have no life of their own. Relationships are predictable and stereotyped: the good daughter, the devoted grandson. The people have no individuality, there is nothing particular about any of them. They are standardised. Simply put, commercial movies do not have people in them.
The film is entirely superficial, content to tell a story and no more. As if the surface level of a daughter defending her father and then discovering he was a war criminal were enough.
There is no creativity, no individual expression or personal point of view in the script. I think that given the same topic, any of a hundred professional script-writers could have written a script interchangeable with the one actually produced.
What annoys me the most is that every emotional reaction of the viewer has been carefully orchestrated and pre-planned by the director. There is no room for emotional ambivalence or individual reaction. Thus the father is entirely a nice guy, until the point when he turns into a monster. There is no attempt to reconcile his two natures. The film-maker manipulates the audience to alternately like him or hate him. We are made to identify with the heroine and to accept the director's point of view. There is no room for ambivalence at the end.
I saw another commercial movie, "Dances with Wolves", which further crystalised my ideas. The film was implausible in various ways and it perpetuated the myth of the noble savage. There was a clear divison into good and bad guys, with hardly anyone in between. The hero was such a moral, noble, sensitive and poetic character that he never did anything wrong. However, what I objected to more than these aspects, and what for me sums up a commercial movie, was something else. Namely that I felt manipulated. At all times I felt that the film-maker was trying to make me feel in a particular way. The viewer is more or less forced to like and admire the Indians and to hate the soldiers. It is all pre-digested.
Generally in commercial movies, there is a clear division into good guys and bad guys. Likewise, issues are presented as being clear-cut, not ambiguous and fuzzy, as they are in real life. In the end there is a neat resolution, though it may be a tragic one. There is a conventional pattern of moving from conflict to resolution.
There is much simplification. The complexity, paradox, fuzziness, quirkyness and intangibility of life are missing. There is an absence of implicit, symbolic or multi-level messages. All is spelt out to the end. Things are not only sensationalised, they are also sanitised, glossing over certain unpleasant or uncomfortable aspects.
Formulas are widely used, not to speak of sequels and imitations. Most commercial movies are easily classified into familiar genres. By contrast, an art movie, if it belongs to a genre at all, tends to transcend it. Films like "The Keep", "Blade Runner", "Butch Cassidy and the Sundance Kid", and "French Connection Part Two" transcend the bounds of the genres of horror, science fiction, western, and thriller respectively.
Commercial movies give us pat answers. By contrast, an art movie is content to ask questions to which there are no easy answers, and perhaps no answers at all. An art film says, "Look at this, what do you make of it?" Whereas a commercial movie tries to make you think and feel in a predetermined way. It does not require much thought or provoke discussion, though the subject is usually controversial, dramatic and laden with emotion.
There is excessive dramatisation. The pace is quick and the viewer is expected to have a short attention span.
The distinction between commercial and art movies is that between an entertainment and a piece of work with something to say that may be of value. Most worthwhile films are not very enjoyable. They are artworks first and entertainments second. In books there is a similar division between pulp fiction and literature. Note this is not simply a division between quality and not: a pulp novel may be an excellent entertainment, while an ambitious literary effort may fail dismally. The distinction is one of intent.
An art film need not be realistic, eg "Testimony". Whereas a commercial movie may appear, on the surface, true to life, yet lack something essential. Thus "Gorillas in the Mist" was too pat, too simple and schematic. Somehow it was all pre-digested for the viewer and over-simplified. This is the essential difference.