These are not my words, and, I can only paraphrase after reading them thirty-seven years ago:

"The two stories being portrayed -- one of the rehearsals and off-stage activities behind the production of a Flamenco Dance version of Bizet's opera, "Carmen," and, the other of the on-stage story, slowly begin to merge until you cannot tell which is reality and which is the scripted story!"

Two friends I watched it with, a co-worker and his wife, I found out after we watched it had met while she'd been studying Flamenco Dance in Spain for a couple of years. They told me that -- excuse me if I get this wrong -- the spirit, "La Duende," of Flamenco, runs through the People of Spain, and that this form of dance and music is intended to be an expression of that spirit -- meant to give voice and form to it. They also explained Paco de Lucia, who's in the film, is (was) the -- oh, what is the term? (preeminent Flamenco player) -- the, "main guy," when it comes to representing Flamenco guitar in Spain, having won that title from his teacher, Andre Segovia (that it was the public opinion, not bequeathed even though it was a topic of some debate).

They also told me that after they met they practiced it together for some time before and after they married.

My co-worker's name, if I remember, is Kirk Prentis. They had two small children, and his hobby was building up early VW station-wagons. I was so sad to find out they were getting Divorced a couple of years later. He'd been in the Navy at some point in the past, and after being stationed in Texas a few years he acquired a t-shirt with an armadillo thats' tale wrapped around the large block letters spelling, "NUKE TEXAS," which, as a Californian, I found hillarious, even though I didn't understand it back then.

This movie is a classic. I highly recommend it, even though you may not get that extra-special dimension of watching with two People in love, who express and can communicate about, "La Duende." And, I also recommend listening to an album (from a concert) called, "Friday Night in San Francisco," where Paco de Lucia plays individually and together with Al Di Meola and John McLaughlin -- also a classic, with it's own lore you can find online.

EDIT: The spiritual side to Flamenco is different and separate from the story of Carmen, which is definitely earthy, or, "of the world," and may not have aged well in today's post-Anita Hill, Me Too era (and, thank you, Anita Hill, for helping shlebs like me understand the error of our ways!)