Conversation so far:
Who was in the Brotherhood of Man lineup?
Brotherhood of Man was formed by record producer/composer Tony Hiller in 1969, and originally featured his co-writer John Goodison with Tony Burrows, Roger Greenaway, Sue Glover and Sunny Leslie.
What albums did Brotherhood of Man have?
United We Stand is the debut album by The Brotherhood of Man. It was released in 1970.
Did Brotherhood of Man do any tours?
Brotherhood of Man toured extensively in Europe, honing their stage act and harmonies, while Hiller, Sheriden and Lee worked on composing songs for their second album.
Who left the original Brotherhood of Man lineup?
Tony Burrows left the group. John Goodison left the group at the beginning of 1971 and was replaced by American singer Hal Atkinson, Roger Greenaway left soon after.

Question: why did they leave
Self-contained rewrite: Why did Tony Burrows, John Goodison, and Roger Greenaway leave the Brotherhood of Man?