Broadway groupies should do cartwheels over this behind-the-scenes documentary that follows the audition process for the revival of “A Chorus Line” that opened in New York in 2006, ended its run there two years later, and is now on national tour. As a piece of cinema, “Every Little Step” is hardly any great shakes, but as a historical document it’s fascinating and compelling.

Most of the footage is of the auditions themselves, beginning with open calls involving literally hundreds of hopefuls and continuing through callbacks and the ultimate selection of the nineteen finalists. It includes excerpts of the performances by the singer-dancers, as well as bits of the comments by the show’s creators, including director Bob Avian (who worked with the legendary Michael Bennett on the original 1975 production) and Baayork Lee (a member of the original cast and now the choreographer), after the individuals have completed their auditions. The suspense exists from the start, but it increases as the numbers of serious candidates are whittled down, until the final act, when in most cases only two performers are competing for each role and a single turn on stage will determine success and failure. Since by that time we’ve gotten to know some of the hopefuls rather well, we can feel their stress and sympathize with the make-or-break nature of the tryouts.

But directors James D. Stern and Adam Del Deo offer additional treasures. Some are snippets from interviews with people like composer Marvin Hamlisch and the first Cassie, Donna McKechnie. And others are archival materials. Perhaps the most precious are excerpts from the original audio tapes of Bennett and others in the workshops in which the show’s book was literally constructed from interviews and personal recollections—a testament to the creative process in itself. But close behind are brief filmed moments from the original production, rarities indeed, which can be juxtaposed against the modern attempts not to duplicate them but to make them live again in different voices and steps.

So Broadway groupies will do cartwheels over it. But “Every Little Step” should appeal to a wider audience, too—in fact, to anyone fascinated by the process of theatrical creation, or artistic invention in the broadest sense, or the simple drive to perform. Cameras have never been allowed behind the scenes in this way before, and one can only hope this won’t be the only time they are.