The documentary "Morning Sun" does a thoughtful job of streamlining the bloody realities - both literal and psychological - of China's Cultural Revolution into roughly two hours of film. The movie, which opens today at the Film Forum, begins with clips from a 1964 "musical extravaganza" - as the narrator, Margot Adler, puts it - called "The East Is Red."

"In dark, old China, the earth was dark, the sky was dark," we hear in a scene from "The East Is Red," and we see a production that looks like a Chinese high school combination of "The Good Earth" and "Porgy and Bess." "The East Is Red," photographed in volcanic color, splashes its propaganda in terms so simple that the scenes become almost Brechtian; more specifically, it's a crude Minnelli musical essentially produced by Mao, the Arthur Freed of Communism.

The pieces of this musical shown in "Morning Sun" are so fulsomely straightforward that being denied a chance to see it in its entirety feels like a form of deprivation. That is, until the directors - Carma Hinton, Geremie R. Barmé and Richard Gordon - focus on the adults who were indoctrinated under the firm, unambiguous hand of Mao.

Then deprivation is defined in truly horrific terms. One describes the Revolution in grimly elegant fashion: "It was an age ruled by both the poet and the executioner; poets scattered roses everywhere, while the executioner cast a long shadow of terror."

One particularly transfixing interview comes from a former Red Guard member whose features are obscured by shadow; his recollections of violence inflicted in Mao's name are darkened by shame. He, like many others, can never quite forgive himself for being sucked into the stream of propaganda; it was a force that, as "Morning Sun" reminds us, molded a new generation into killers without any sense of the long and tortured history of a China that existed before Mao brutally eliminated all traces of it.

"Morning Sun" effectively explains Mao's strangulation of outside influences, cutting off the Western arts that were still offered to children until the 1960's. Another spellbindingly simplistic film played a big part in Communist China - a 1955 Russian movie adaptation of "The Gadfly," an 1897 novel by Ethel Lilian Voynich.

Clips from this operatic Italian-set story of Arthur, a man rejecting all the lessons of his youth, including those of the church, are shown in "Morning Sun." Arthur confesses his loss of faith to his mentor, a priest, who turns the young man in to the authorities - a priest who is later revealed to be his father. The ideals exposed in the wildly overstated "Gadfly" - the protagonist later becomes a heroic revolutionary - took hold of Chinese youth. (It also similarly affected Russians, according to "Morning Sun.") And as young Communists age, the movie's impact shifts with them. Eventually "Gadfly" was too complex for Mao, who removed it from circulation in favor of one-dimensional dramas that were far more blatant. When "Gadfly" is finally available and its fans see it again as adults, the movie's impact - and the eddies of the father-son-revolutionary - takes on other shadings; it's the losses in the relationships that resonate for them.

One of the few subtle points of "Morning Sun" is that even simple, lurid dramatic tragedy looks different to its admirers as they mature. The eloquence of the interview subjects - and the clips - have a power that the written narration, which tends to sound like an "All Things Considered" segment, often lacks. And, as in "Gadfly," loss echoes throughout this documentary, too.

"Chairman Mao said, 'You young people are like the morning sun; our hope is placed on you,'" remembers Li Nanyang, who was a child of 1960's China. And as "Morning Sun" unfolds, she is shown to be one of the Cultural Revolution's victims. Her father, Li Rui, who rose through the ranks to become Mao's secretary, made the mistake of criticizing a failing policy during the Great Leap Forward in the 1950's, when farms were converted into small factories and the resultant shortages nearly crippled the nation; his reward was being publicly repudiated and sent away, and his daughter, 9 at the time, was ridiculed until she denounced him.

"Morning Sun" ends with a reunion of father and daughter after 11 years.

"Finally, I was free to speak my mind, unlike 1967," Li Rui says, and the familial resemblance - a proud, strong mouth - is evident. "I finally came out with it, and he cried," his daughter says, remembering when she called him Dad, something she wasn't permitted to do since his disgrace. The movie closes with this scene, the ascension of a different sun.