https://archive.md/2021.12.17-113002/https://www.washingtonpost.com/world/2021/12/17/china-dancing-grannies-noise/

Guangchangwu, or “square dancing,” dates back decades. The practice had its origins in collective public dances during the Cultural Revolution in the 1960s and 1970s, and later in the economic reforms of the 1990s that left many city dwellers jobless and in need of low-cost entertainment.

Today, the "damas” or “big mothers” as the dancers are known, can be found dancing in the early mornings and evenings, blasting their stereos, waving fans and scarves, while jitterbugging, waltzing and jiving.