When the critical eye of Mao Zedong's wife fell upon a non-conforming artist during China's Cultural Revolution the assessment could be devastating.

The consequences may be less brutal now, but China's Communist authorities still impose strict controls and censorship.

Jiang Zuhui, now 81, choreographed one of the most emblematic works of the Cultural Revolution era -- the "Red Detachment of Women" ballet.

When she fell out with Mao's powerful wife Jiang Qing and labelled "counter-revolutionary", she was detained in a rehearsal room at her theatre for nearly three years, before being "sent down" to the countryside for more than half a decade.

Many other artists faced a similar fate, while others were persecuted, tortured, even killed.

"Artists lost 10 years," Jiang said of the Cultural Revolution, which was proclaimed 50 years ago on Monday.

"Everything stopped. It was a waste."

Mao's wife, a former actress declared a patron of culture, launched a campaign to cleanse the arts: all plays, films, operas, ballets and music considered "feudalistic and bourgeois" were banned.

Her ex-colleagues in the Shanghai film industry -- along with previous lovers -- were said to be among her first victims.

The "Red Detachment of Women" -- which tells the story of a 1930s Chinese woman who escapes a cruel master and joins a female battalion of the then underground Communist Red Army -- was one of eight "model performances".

Chosen by Mao's wife, they were the only artistic works allowed to be mounted during the period and she took close control over the few troops authorised to produce them.

"Once she came to attend one of our rehearsals," recalled Jiang Zuhui.

"At the end, I invited her to go on stage to join the artists. She refused. I insisted politely, and she took it for insolence."

Now retired and living in Beijing, she told AFP: "To oppose Jiang Qing was to oppose the revolution."

It was the beginning of her nightmare, which ended only with her tormentor's fall following Mao's death in 1976.

- Cultural disaster -

The Cultural Revolution was "a disaster for the arts and literature", said art critic Zhu Dake.

Art became a "political tool", he said. "In total, maybe 1 in 10,000 (artists) were allowed to continue to work, but only on model plays."

Today the risk of artistic banishment has receded -- although dissident artist Ai Weiwei was denied a passport for years -- but current President Xi Jinping has declared that culture must serve the ruling Communist Party.

The "Red Detachment of Women" remains part of the repertoire of China's National Ballet, along with once-banned foreign works such as Carmen and Don Quixote.

But in general "red shows" glorifying the Communist Party aren't very popular.

State-owned enterprises regularly offer their employees free tickets to such performances, but employee Xiao Deng said that "only a few older people are nostalgic" for them.

"Young people do not feel concerned by these stories, which are so different from their aspirations and their lives today."

Even so, Xi -- in a speech that drew comparisons to a 1942 address by Mao -- recently urged China's artists not to chase popularity with "vulgar" works but promote socialism instead.

Xi's speech has been published as a book -- with chapter titles including "Strengthening and improving the Party's leadership over artistic practice" -- and local authorities have been encouraged to organise seminars to disseminate its contents, state media reported.

"Art and culture will emit the greatest positive energy when the Marxist view of art and culture is firmly established and the people are their focus," Xi said, according to a transcript released by the official news agency Xinhua.

In the aftermath of the Cultural Revolution there was a "rebirth" of novels, painting, theatre and fine arts, critic Zhu told AFP, but it "ended in 1989" -- the year of the Tiananmen square crackdown.

Artists were freer now than in the extremes of the late 1960s, he said, but added: "Today there is no space for creation. Under the twin pressures of commerce and politics, artists have no real room to grow."