do you mean: more famous than many singers?
The show was probably, "The Beverly Hillbillies," and the theme song was performed by "Lester Flatt, Earl Scruggs, and the Foggy Mt. Boys."
Bluegrass as a style developed during the mid-1940s. Because of war rationing, recording was limited during that time, and it would be most accurate to say that bluegrass was played some time after World War II, but no earlier.
As with any musical genre, no one person can claim to have "invented" it. Rather, bluegrass is an amalgam of old-time music, country, ragtime and jazz. Nevertheless, bluegrass's beginnings can be traced to one band. Today Bill Monroe is referred to as the "founding father" of bluegrass music; the bluegrass style was named for his band, the Blue Grass Boys, formed in 1939.
Rural (country) and urban
Most of the Appalachian settlers came from Germany as well as the UK countries of Scotland, England and Ireland.
Earl Scruggs and Lester Flatt
(Apex) - Close to the Atlantic Coast
Appalachian
The field-holler
The songs were connected to life and daily functions.
Folk music was invented in the 1930s by Woody Guthrie and Pete Seeger.