Country rock was a particularly popular style in the California music scene of the late 1960s, and was adopted by bands including Hearts and Flowers, Poco (formed by Richie Furay and Jim Messina, formerly of the Buffalo Springfield) and New Riders of the Purple Sage. Some folk-rockers followed the Byrds into the genre, among them the Beau Brummels and the Nitty Gritty Dirt Band. A number of performers also enjoyed a renaissance by adopting country sounds, including: the Beatles, who re-explored elements of country in their later albums, like "Rocky Raccoon" and "Don't Pass Me By" from their eponymous "White Album" (1968), and "Octopus's Garden" from Abbey Road (1969); the Everly Brothers, whose Roots album (1968) is usually considered some of their finest work; former teen idol Ricky Nelson who became the frontman for the Stone Canyon Band; John Fogerty, who left Creedence Clearwater Revival behind for the country sounds of the Blue Ridge Rangers(1972); Mike Nesmith, who had experimented with country sounds while with the Monkees, formed the First National Band; and Neil Young who moved in and out of the genre throughout his career. One of the few acts to successfully move from the country side towards rock were the bluegrass band the Dillards.
By the end of World War II, "mountaineer" string band music known as bluegrass had emerged when Bill Monroe joined with Lester Flatt and Earl Scruggs, introduced by Roy Acuff at the Grand Ole Opry. That was the ordination of bluegrass music and how Bill Monroe became to be known as the "Father of Country Music." Gospel music, too, remained a popular component of bluegrass and other sorts of country music. Red Foley, the biggest country star following World War II, had one of the first million-selling gospel hits ("Peace in the Valley") and also sang boogie, blues and rockabilly. In the post-war period, country music was called "folk" in the trades, and "hillbilly" within the industry. In 1944, The Billboard replaced the term "hillbilly" with "folk songs and blues," and switched to "country" or "country and Western" in 1949. https://www.youtube.com/watch?v=hyNAvdnZ5Ec