Short answers, pulled from the story.
Disco emerged in the late 1960s from the urban nightlife of New York City and Philadelphia. This new sound grew from African-American, Latino, Italian-American, and queer communities who sought escape in dance clubs.
The first discotheques appeared in Paris during the Nazi occupation of the early 1940s when jazz records replaced live bands. Régine Zylberberg claimed to have started the first discotheque in 1953 at the Whisky à Go-Go club.
Disco features four-on-the-floor beats set by a bass drum hitting once per beat with syncopated basslines playing broken octaves. String sections and horns play linear phrases in unison with soaring vocals while electric pianos create background pads.
By 1979 there existed between 15,000 to 20,000 disco nightclubs across the United States. Many opened in suburban shopping centers, hotels, and restaurants including The 2001 Club franchises which represented the most prolific chain.
Disco declined as a major trend following infamous Disco Demolition Night on the 12th of July 1979. It continued sharp decline during early 1980s United States but remained popular in Italy and some European countries throughout the 1980s.