Monroe was born on his family's farm near Rosine, Kentucky, the youngest of eight children of James Buchanan "Buck" and Malissa (Vandiver) Monroe. His mother and her brother, Pendleton "Pen" Vandiver, were both musically talented, and Monroe and his family grew up playing and singing at home. Bill was of Scottish heritage. Because his older brothers Birch and Charlie already played the fiddle and guitar, Bill Monroe was resigned to playing the less desirable mandolin.
Professional career
In 1929, Monroe moved to Indiana to work at an oil refinery with his brothers Birch and Charlie, and childhood friend and guitarist William "Old Hickory" Hardin. Together with a friend Larry Moore, they formed the "Monroe Brothers", to play at local dances and house parties.  Birch Monroe and Larry Moore soon left the group, and Bill and Charlie carried on as a duo, eventually winning spots performing live on radio stations-- first in Indiana and then, sponsored by Texas Crystals, on several radio broadcasts in Iowa, Nebraska, South Carolina and North Carolina from 1934 to 1936. RCA Victor signed the Monroe Brothers to a recording contract in 1936. They scored an immediate hit single with the gospel song "What Would You Give in Exchange For Your Soul?" and ultimately recorded 60 tracks for Victor's Bluebird label between 1936 and 1938.  After the Monroe Brothers disbanded in 1938, Bill Monroe formed The Kentuckians in Little Rock, Arkansas, but the group only lasted for three months. Monroe then left Little Rock for Atlanta, Georgia, to form the first edition of the Blue Grass Boys with singer/guitarist Cleo Davis, fiddler Art Wooten, and bassist Amos Garren. Bill had wanted "Old Hickory" to become one of the original members of his "Blue Grass Boys", however William Hardin had to decline.  In October 1939, Monroe successfully auditioned for a regular spot on the Grand Ole Opry, impressing Opry founder George D. Hay with his energetic performance of Jimmie Rodgers's "Mule Skinner Blues". Monroe recorded that song, along with seven others, at his first solo recording session for RCA Victor in 1940; by this time, the Blue Grass Boys consisted of singer/guitarist Clyde Moody, fiddler Tommy Magness, and bassist Bill Wesbrooks.  While the fast tempos and instrumental virtuosity characteristic of bluegrass music are apparent even on these early tracks, Monroe was still experimenting with the sound of his group. He seldom sang lead vocals on his Victor recordings, often preferring to contribute high tenor harmonies as he had in the Monroe Brothers. A 1945 session for Columbia Records featured an accordion, soon dropped from the band. Most importantly, while Monroe added banjo player David "'Stringbean" Akeman to the Blue Grass Boys in 1942, Akeman played the instrument in a relatively primitive style and was rarely featured in instrumental solos. Monroe's pre-1946 recordings represent a transitional style between the string-band tradition from which he came and the musical innovation to follow.
What profession does he have?
sang
sang