Premise: Ronald Belford `` Bon '' Scott ( 9 July 1946 -- 19 February 1980 ) was an Australian rock musician , best known for being the lead singer and lyricist of Australian hard rock band AC/DC from 1974 until his death in 1980 . He performed in several other bands including The Valentines and Fraternity before replacing Dave Evans as the lead singer of AC/DC in 1974 .
Hypothesis: In the year 1974, Bon Scott became AC/DC's lead singer.
Label: ENTAILMENT