Sock hop

Sock hops were held as early as 1944 by the American Junior Red Cross to raise funds during World War II.

The term came about because dancers were required to remove their hard-soled shoes to protect the varnished floor of the gymnasium.

[1]: 200  The music at a sock hop was usually played from vinyl records, sometimes presented by a disc jockey.

[1]: 199–200  In subsequent decades, with the widespread popularity of sneakers and other types of indoors-only footwear, the practice of removing shoes was dropped.

[4] The term caught on in England in the late 1980s during a British rockabilly revival, led by groups like The Stray Cats.