To an ear-splitting soundtrack of chanting and drums, 400 young dancers in spangled outfits clanged sickles and kick-stepped before thousands of spectators and a dais of a dozen Chinese officials.

The performance was one of many at Leishan county in the southwestern province of Guizhou, as a lavish government-sponsored opening ceremony kicked off new year celebrations for the Miao ethnic minority -- a group of about 12 million people who are more at home in their own languages than in Mandarin Chinese.

The songs and dances being performed were once used to enliven back-breaking agricultural labour in the mountainous region, one of China's poorest.

"When I was young, I had to go out and harvest rice -- it was so tiring, and so precious that old people would pick up and eat even a single grain of rice that fell on the floor," said Yu Nianlan, a Miao native of Leishan who now works an office job but could recall such traditions from her childhood.

"Now China is rich and strong, and that's no longer necessary for our family," she told her six-year-old son, who was more interested in watching the drones that buzzed overhead capturing aerial footage of the dance formations than in listening to her explain their origins.

Thousands of performers ranging from seven-year-olds to octogenarians took part in the extravaganza, which began with a parade through the city to the arena earlier in the afternoon.

They marched in groups by region, with each sporting clothing unique to the subgroup of Miao found in that area.

Some wore head-to-toe embroidered outfits with trailing ribbons and fringe, others indigo hemp jackets lacquered with raw eggs to have a plastic-like sheen. Silver headpieces shaped like flowered crowns or bull's horns shimmered in every direction.

Clusters of tiny Miao grandmothers sporting thick silver earrings thronged the streets, while tourists mingled with families buying sugar-coated red hawthorn fruits on sticks and plastic noisemakers for the kids.

A Han tourist from Chongqing surnamed Zhou, one of many male photographers pushing a telescopic lens into the faces of passing Miao girls, asked one parade sign-holder in a long pleated skirt: "How can you be just 15, and already so pretty?"

China's ruling Communist party recognises 56 different ethnic groups, and official propaganda seeks to emphasise harmony and unity among them.

For the show's finale, all the performers marched in a large spiral around a knot of reed pipe-players, as an operatic singer warbled: "All the Miao people in the world are one family!"

Ten-year-old He Chenxi admitted that not all her fellow dancers were Miao, however.

"Our teachers picked anyone who had long enough hair," she explained, indicating her elaborate topknot embellished with a bright red flower.

Nevertheless, first-time Miao performer 16-year-old Song Yunrong felt honoured to play her role.

"It's a great thing that the government does this on such a big scale, to bring our hometown fame," she said.

"Sometimes I feel bothered because the massive number of tourists will ruin the environment here, but things always have two sides to them."