Original sentence: John Peter Farnham, AO (born 1 July 1949) is an English-born Australian pop singer who performed as teen pop idol, Johnny Farnham, from 1964–1979 and then as adult contemporary singer John Farnham
Edited sentence: He was a teen pop idol known as Johnny Farnham from 1964–1979, and since then has  forged a career as an adult contemporary singer.John Peter Farnham, AO (born 1 July 1949) is an English-born Australian pop singer