Of all the youthful rebellions of the 1960s, the weirdest and least understood has to have been China's Cultural Revolution. As in America, France, and elsewhere, college students banded together, took to the streets, and wreaked outraged violence against their parents' generation. The difference is that they were working for the government -- in particular, in response to the urgings of Communist Party chairman Mao Zedong, who set the hordes against his own ruling elite in a bizarre and perverse bid to keep the Revolution honest.

It's as though Richard Nixon had personally handed out the Molotov cocktails and invited the Weathermen to the Capitol.

All right, not really, but Mao was a genius at creating a cult of personality that served his own political ends. Sensing that a new generation was coming up that a) had no memories of pre-Revolution China and b) felt cheated out of the heroic struggle their elders had waged, Mao kindled the dissatisfaction until it burst into the flame of the Red Guards -- student organizations that roamed the country, beating and sometimes killing intellectuals, party leaders, and anyone deemed "counterrevolutionary."

Like all mass movements, the Cultural Revolution was strident, idealistic, and deadly. It allowed Mao to purge several of his rivals; it also sank the country into chaos from the mid-1960s until the Chairman's death in 1976. "Morning Sun," a documentary made by the Brookline-based Long Bow Group that is playing at the MFA until Nov. 1, is the first film to stand back and take a good, hard look at the era, and it has the force of shameful secrets being hung out in the air.

At nearly two hours and with overly dry narration by NPR correspondent Margot Adler, "Morning Sun" has its dusty moments. It's saved, time and again, by an astonishing archival mix of propaganda and news footage, as well as firsthand accounts of those who were there. Structured chronologically, the film begins with scenes from the 1964 Peking Opera stage extravanganza "The East Is Red" -- a hugely popular event that, for the young, carried a psychological force akin to the Beatles appearing on Ed Sullivan. The 1955 Russian film "The Gadfly" also proved crucial to the new generation's socialist-martyr yearnings. As with youth movements elsewhere, the movies fused rebellion and romance better than other media.

Prompted to speak out against enemies of the revolution, a Beijing University faction called themselves the Red Guards, aimed criticism directly at the country's inner circle, and called for a new revolution -- "the messier, the better." To the shock of all, Mao agreed, positioning himself as a benevolent father-figure/godhead and stoking the fervor until it erupted into indiscriminate violence. "How could students from such a school go from being nice girls to being murderers?" wonders one of the interviewees, and then partially answers her own question: "In the past, grown-ups never took us seriously."

"Morning Sun" gives us voices from across the spectrum, including one of the founders of the Red Guards, his face in shadow and his words filled with regret. We hear from the brother of a student newspaper editor who was executed when the Cultural Revolution started consuming its critics. The widow and daughter of scapegoated President Liu Shaoqi are interviewed; so are Li Rui, a Communist Party veteran who was exiled by the Red Guards, and his daughter Li Nanyang. The latter speaks of her rejection of her father -- of her being too rigid to even call him "dad" -- and how saying that word ultimately helped break her doctrinal fever.

Perhaps the most telling quote -- the one that underscores why this upheaval was different from all the others of its time -- comes from former student Zhu Danian. "Why did we fight for the right to make revolution and not some other right?" he asks. "Because there were no other rights."