The situation is as follows: A onetime movie idol, his career and confidence in ruins, makes a daring move into a new medium. His livelihood, his sense of value, maybe even his life are at stake. But nefarious forces within the entertainment industry, like snakes around his ankles, conspire to thwart his efforts on behalf of art and his own reinvention.

“Birdman”? No, “Singin’ in the Rain,” the 1952 Gene Kelly/Stanley Donen classic set on the cusp of silent film and sound, and a movie that’s a lot of things — an infectious musical, an affectionate romance, a well-cultivated cultural artifact. But hardly a documentary about showbiz. Few of the myriad movies about movies have been, of course, despite a catalog of self-referential fare that ranges from “Sullivan’s Travels” to “Boogie Nights,” from “Living in Oblivion” to “A Star Is Born,” from “Day for Night” to “Wes Craven’s New Nightmare.”

“There’s a gazillion of them,” says Dave Kehr of the film department at the Museum of Modern Art in New York. “There’s even sort of a subgenre about how snotty New York theater people look down on movies. And most of these were written by snotty New York theater people.” One example: George S. Kaufman’s “Once in a Lifetime,” in which “New York writers come out during the talkie boom and find the studios run by, of course, idiots, and are able to take over and con everybody. Pure fantasy.”

He says one curious thing about movies about movies is that, with the exception of perhaps “In a Lonely Place,” they almost always lie about how movies are made.

“Everybody goes to the soundstage and does this elaborate production number, which is carefully edited from five different camera positions, and all you see is one guy shooting the whole thing,” Kehr says. “Nothing about the actual painful detail involved.”

Distorting the process is a way of making it all seem more simple, or more spontaneous, just capturing what’s in front to the camera, and that is the illusion Hollywood always wants to create. A spectacular example is “The Artist,” which ends literally with the cast all going out and doing a production number that emerges whole as they’re shooting it.

What’s consistent about movies about movies — a genre that dates back to the Edison Studios — is that they always seem to be about transformation, which makes sense: The near-miraculous alchemizing of light, words and chemicals (or pixels) into entertainment art makes cinema synonymous with change and reimagination. And given that a byproduct of transformation is redemption, it makes sense that saving one’s soul would be the other theme of films about film:

In “Singin’ in the Rain,” Gene Kelly’s character is trying to transition into talking pictures and save his career and sense of self. In “A Star Is Born” the Janet Gaynor/Judy Garland character is trying to balance success with love, save her marriage and salvage her husband. In Robert Altman’s “The Player,” Tim Robbins tries to balance success and homicide to save his cushy studio job. (OK, that one’s kind of an outlier.) In “All That Jazz,” “Barton Fink” and even “Ed Wood,” as wacky as it is, artists try to realize their vision while fighting the champions of mediocrity and/or common sense.

In “Birdman,” Michael Keaton’s character is trying to transition from a blockbuster franchise to the Broadway stage to save his questionable sanity.

“We always thought our film was really about a man battling his own ego,” says “Birdman” producer John Lesher. “Trying to find meaning in his life, and trying to find redemption personally, and artistically and what lengths he will go to in order to find that. He puts everything on the line — does he succeed? Or not? And does he succeed in the way he wanted?”

These are universal truths, Lesher says. “In this case Riggan Thomson is an actor, but these are the same themes all human beings battle as we go through life. We’re all fathers and sons and daughters, and to me, that’s what the movie had to be about.”

Many filmmakers would heartily agree.