Bluegrass is the common name for more than 250 species of annual and perennial narrow bladed, spikeless, bristleless, open clustered, blue-green grasses that grow in cool and temperate climates.The best known of these species grows in such abundance throughout central Kentucky that Kentucky is nicknamed The Bluegrass State. Bluegrass came to be used as a musical term because of Bill Monroe, the acknowledged "Father of Bluegrass Music."

 Bill Monroe and his brother, Charlie, were one of the most popular musical duet teams of the 1920's and 1930's. With Bill on mandolin and Charlie on guitar, they sang the old time music of the rural Southern mountains. In 1938, they split up as a team and each brother formed his own band. Since Bill was a native of Kentucky, he called his band "Bill Monroe and the Blue Grass Boys." This new band differed from other traditional music bands of that time because it used acoustic instruments and highly distinctive vocal harmonies with songs and rhythms from string band, black and white gospel, work songs, country, and blues music repertoires. Bill settled on mandolin, banjo, fiddle, guitar, and bass as the instrumental format for his band and to them he added his own "high and lonesome" solo lead singing. Bill Monroe and the Blue Grass Boys first appeared on the Grand Ole Opry in 1939.

 Bluegrass music sounds old because it is a synthesis of many older styles of music. Most people believe that the classic bluegrass sound did not jell until 1946, when a 21 year old banjo player from North Carolina named Earl Scruggs joined Bill Monroe's band. Scruggs played his own three finger picking style which has come to be known as "Scruggs style" banjo. Equally influential in that classic 1946 line up were Lester Flatt on guitar, Chubby Wise on fiddle, and Howard Watts on acoustic bass. Flatt sang lead vocals against Monroe's high tenor and bluegrass music was born.
 First Earl Scruggs and then Lester Flatt left the Blue Grass boys, and eventually they formed their own band: The Foggy Mountain Boys. Flatt and Scruggs were the first to add the Dobro (resophonic guitar) to their band format. In 1949, Burkett "Uncle Josh" Graves heard Scruggs' three finger banjo picking and adapted it to the Dobro. Graves played with Flatt and Scruggs from 1955 to 1969.

 From 1948 to 1969, Flatt and Scruggs were a major force in bringing Bluegrass music to the American audience through recordings, television and live concert appearances. Scruggs wrote and recorded "Foggy Mountain Breakdown," one of bluegrass music's most famous instrumentals, which was used in the soundtrack for the film Bonnie and Clyde. In 1969, Scruggs began a solo career, performing with his three sons as The Earl Scruggs Revue. After parting with Scruggs in 1969, Lester Flatt performed steadily with his own group, The Nashville Grass, until his death in 1979.

 Bluegrass is now an accepted musical genre throughout the world. The IBMA (International Bluegrass Music Association) claims members in all 50 states and in 30 foreign countries. The classic bluegrass style born in 1946 is still widely performed, but bluegrass bands now reflect of musical influences that range from traditional and fusion jazz to Celtic music and rock&roll. In May, 1977, Bill Monroe was inducted into the Rock and Roll Hall of Fame because of the profound influence of his music on popular music in America. Bill Monroe died on September 9, 1996, four days before his 85th. birthday.