The music was an electric organ playing "Pistol Packing Mama." The decor at the cultural palace of nationalities: flashing multi-color lights on evergreen trees. And while the guests didn't look very different from a Saturday night crowd at a fraternal club in western Maryland, the two couples on the dance floor certainly did. The men were in tweed suits, their "Superman" jackets extending a foot on each side beyond the shoulder line. One woman was wearing a black leather jacket with padded shoulders that swooped up at least 3 inches, the other a similar style in black velvet. Ti was Pierre Cardin with three of his models at "the Studio 54 of Peking," celebrating what Cardin called "the most important fashion show of my life"-three fashion collections presented in Peking followed by two more in Shanghai.

"There is nothing so bad about everyone wearing the same clothes every day," said a relaexed Pierre Cardin sipping a glass of tea in the near-empty dining room at the Min Sui Hotel in Peking. He had just returned from the Great Wall where models wearing his bare top evening dresses were photographed for Paris Match. "It saves the trouble of having to make a choice." (He also photographed his clothes in front of wall posters in Tien An Mien square in Peking.)

But in fact, Cardin's modernization program for China-initeated by an invitation from the Chinese government to show his clothes here and advise the clothing and textile industry-was belying his tongue-in-cheek observation.

Cardin had packed up his 200-piece collection in Paris to take to Peking with sex French models. At the last minute, he ordered his workroom to make 20 more pieces in what he called "China size" and added three models from China when he got there.

According to Cardin, guests were mostly members of the People'e Republic of China trade association. Sharon Woodcock, wife of the ambassador and one of the five ambassadors' wives to attend the second Cardin show, says many of the women recognized their local tailors in the audience, but aslo present, she said, were men and women in the People's Republic of China green army uniform.

"The Chinese simply stared in amazement, occasionally nudging each other and whispering," said Woodcock. First, out came the suits, dresses and coats, many the style with swooping shoulders that Cardin calls "the Pagoda look." Then there were seethrough tops that positively stunned the puritanical Chinese, according to Woodcock. The bride in traditional white aslo was a surprise, particularly when she and the groom hugged at the end of the runway-a display of affection almost never seen publicly in China. When it was over, the usually reticent audience applauded locudly.

Cardin isn't counting on the Chinese to fill in for the Iranian customers he lost because of the current political atmosphere and the return to veiled costumes there. The lost Iranian business is being generously repaced by the Arabs, he said, "but most Arab women are not elegant as the Iranians. Arab women buy clothes just to spend money and choose flashy rather than stylish dresses."

Cardin knows the Chinese woman, whose average income is $25 per month, are unlikely customers for his designs. "But there is so much about America and the West on TV and newspapers here, I'm sure that the Chinese will be in Western clothes in five years," he said.

His show was just to provoke the Chinese to think about styles other than the popular blue jacket and pants unisex costume.

But at the dance that night (a public twice-weekly event where you can order tea, beer, vodka or whiskey), the first Chinese to make actual contact with the Cardin clothes was not very enthusiastic. Cardin's nearly 6-foot-tall directress, Maryse Gaspard, approached several Chinese men who had slipped into the dance and were sitting quietly against the wall, and asked them to dance. The Chinese waved their hands in front of their faces in refusal, the way Chinese do when they don't wish to be photographed.

Cardin was sure they weren't turning down his new style clothes. "I'm sure they loved them," he said. "Only the boldness of the models frightened them."