As always I'll preface my comments with the usual I'm not a professional at this by any stretch of the imagination, and I beg forgiveness from the professionals in advance.
I have been, especially since I began my career in the film aspect of the entertainment industry, a fan of commentaries and BTS. There is comparatively little out there for Sound-For-Picture folks like myself. Consequently I go through all of it. Although there are a few gems like Randy Thom discussing discussing "Forrest Gump" and the marvelous BTS with Ben Burtt on the "Wall E" DVD, with some fine vids on YouTube, I have been forced to search for those informative nuggets in the rest of the extra content.
One of my favorite films is "The Adventures Of Robin Hood," (1938), the movie that codified and set the standard for action/adventure films for years to come. Richard Behlmer, during his excellent commentary (worth a listen; it's nice insight into the workings of the studio system during Hollywood's golden age) relayed a number of things from stunt coordinator and sword-master Fred Cravens. The first was the difference between reality and entertainment. In cinematic fighting the duelers exaggerate their moves, which telegraphs their intent, contrary to actual sword fighting techniques. The second was that Basil Rathbone was the best film duelist Cravens had ever seen, and could have been a professional if he had chosen that career path. The same was said of Viggo Mortensen regarding both sword
and horse in the "Lord Of The Rings" BTS.
This sort of stuff always sends me down the rabbit hole. What interested me - and the pros can correct me if I'm wrong - is that in the day of heavy swords and large shields the first blows were to check your opponents style and strength, then proceeded to a proscribed sequence of moves, to which there was an established counter. You then used a new sequence. The swordsman either found a sequence, his opponent did not know, used a unique variation in an existing pattern, or simply wore his opponent down in a test of endurance until his foe was vulnerable to a killing strike. New work (happily) arrived at this point and I was unable to follow the rabbit further.
We've all seen boxers do the same thing; they throw a few punches at the head and a couple at the body as tests, then move on to a sequence of punches. Pitchers use sequences in baseball; if they can accomplish what they want these sequences and their variations can fool the batter. ("Field of Dreams" - "...but watch out for in your ear."
) I learned similar things myself when I wrestled in junior high school; if he does this you do that.
I don't know if it applies to combat sports, but it seems to me that things are almost formalized in some way. The point of all this is that I don't believe you can cinematically copyright the formalized sequences, but rather that it is the
interpretation that can be copyrighted. Aside from the films value in and of itself - cinematography, set design, etc. - it is the sequence of sequences, the unique approach to what is previously established. From my music background... You cannot copywrite a chord sequence or a scale or and interval. As an example, the interval of root note and the major fifth above it. Duuuuu Daaaaa. It is the variations - the interpretation - that can be copywritten. Imagine a stereotypical horn call (like from Robin Hood); Duuu Du Du Daaaaaa versus Du Daaaaa Du Daa Du Daa Du Daaaaaaaaaaa. It has even been argued, quite vociferously, even in courtrooms, that simply changing the key, even if it's the same pattern and tempo, is enough to avoid infringement. And even in the courts those issues are up to the interpretation of the lawyers, their experts and the jury.
As a musician I, like so many others, learned the basics and the "traditional" songs. I played literally hundreds of copy/cover songs in my career. When I got into the studio I would take all that - you are trying to make hit songs, right? - and would use currently popular things and put my own personal spin on it.
Th whole point of all this meandering drivel is that it's all about creating a unique interpretation of established norms. Take a section from this film, another from that one, etc. and create something of your own.
If you are copying just to learn that's great too, but is an entirely different issue.
I hope that this has helped.