Final answer:
The 1972 song "Love Train" by The O'Jays is often considered the first Disco hit, marking a significant milestone in the genre's history.
Step-by-step explanation:
The 1972 song that is considered to be the very first Disco hit is "Love Train" by The O'Jays. Disco music, which evolved from funk, soul, and Latin styles in the early 1970s, became synonymous with the dance music movement of that decade.
The genre gained popularity in dance clubs and eventually on radio stations, paving the way for many subsequent Disco hits. "Love Train" captured the upbeat and rhythmic essence that would come to define Disco music, making it a significant milestone in the genre's history.