Singer and guitarist Lester Flatt and banjo player Earl Scruggs, both of whom had been members of Bill Monroe's band, the Bluegrass Boys, from 1945 to 1948, formed the duo in 1948.

Flatt and Scruggs are viewed by music historians as one of the premier bluegrass groups in the history of the genre.

[1] Their backing band, the Foggy Mountain Boys, included fiddle player Paul Warren, a master player in both the old-time and bluegrass fiddling styles whose technique reflected all qualitative aspects of "the bluegrass breakdown" and fast bowing style; dobro player Uncle Josh Graves, an innovator of the advanced playing style of the instrument now used in the genre; stand-up bass player Cousin Jake Tullock; and mandolinist Curly Seckler.

[2] Scruggs, who had always shown progressive tendencies, experimented on duets with saxophonist King Curtis and added songs by the likes of Bob Dylan to the group's repertoire.

24 on CMT's 40 Greatest Men of Country Music, one of only four non-solo artists to make the list (Eagles, Alabama, and Brooks & Dunn are the others).