Here's a good timeline on disco and it parallels my experience in San Juan which was a true disco "hotbed" in the era... remember, WKTU in New York exploded initially with the huge second generation Puerto Rican community and the station was owned by a Puerto Rican company.Disco had been slowly fading out by 1978. Saturday Night Fever propped it back up for awhile, but Disco Demolition was the final nail in the coffin.
53 essential No. 1 disco hits | The Spokesman-Review
Forty years ago Sunday, “Funkytown” by Lipps Inc. hit No. 1 on the Billboard Hot 100 singles chart, becoming the final big hit of the disco era. Here’s a look at 53 essential No. 1 disco hits to help you remember how to shake, shake, shake your booty.
Disco did not start fading in 1978. It was, in fact, July 24 1978 that KTU in New York began its disco format, and it had two years at a dominent #1 in the market with that music. As 1980 ended, KTU stopped using "disco" and called itself "the hot one" and gradually faded until a format change in 1985.
I've always considered "Rock the Boat" the first hit that ushered in an era, as within just a few months of its release, we were flooded with product. And Funkytown was the last huge hit.
In most of the Americas, the almost "sudden death" of disco had nothing to do with a rock jock in Chicago dissing the music. Disco just burnt out like an intense fire that had nothing new to fuel it.