Conversation so far:
What profession does Bill Monroe have?
Bill Monroe was an American mandolinist, singer, and songwriter.
When did Bill Monroe start singing?
Bill Monroe's mother and her brother, Pendleton Pen Vandiver, were both musically talented, and Monroe and his family grew up playing and singing at home.
Where did Bill Monroe first perform?
In 1929, Bill Monroe with his brothers Birch and Charlie, friend William Hardin, friend Larry Moore, formed the Monroe Brothers, to play at local dances and house parties.
How did Bill Monroe progress from there?
Birch Monroe and Larry Moore soon left the group, and Bill Monroe and Charlie Monroe carried on as a duo, eventually winning spots performing live on radio stations

Question: When did he eventually get signed?
Self-contained rewrite: When did Bill Monroe eventually get signed?