1957 Rock & Roll - Sock Hop
Sock hops were held as early as 1944 by the American Junior Red Cross to raise funds during World War II. They then became a fad among American teenagers in 1948. Sock hops were commonly held at high schools and other educational institutions, often in the school gym or cafeteria. The term came about because dancers were required to remove their hard-soled shoes to protect the varnished floor of the gymnasium. The music at a sock hop was usually played from vinyl records, sometimes presented by a disc jockey. Occasionally there were also live bands.
In later years, "hops" became strongly associated with the 1950s and early rock and roll. Danny and the Juniors sang "At the Hop" in 1957, which named many popular dances and otherwise documented what happened at a hop. In subsequent decades, with the widespread popularity of sneakers and other types of indoors-only shoes, the practice of removing shoes was dropped. The term then came to be applied more generally to any informal dance for teenagers.