Garth Brooks killed it with his Rock-a-Billy. But that wasn't the first time "Country" music was killed off and reborn as something completely different. And it won't be the last.
I maintain that when Disco, New Wave, and Punk killed off Country-Rock (e.g., The Eagles) and Folk-Rock (e.g., Nicolette Larson), Country inevitably became more pop and filled the enormous void. I consider Garth Brooks the consequence rather than the catalyst.
The pop, slick, side of Country has indeed been around for a long time; it just was not as mainstream and profitable. The Anita Kerr Singers, working with various studio musicians such as Floyd Cramer (piano), created the Nashville Sound, which provided the backing vocals to a broad spectrum of musical hits in Country and Pop.
Kerr, born in Memphis, Tennessee, was a marvelous soprano, and a very gifted arranger. Her influence across many genres of popular music is enormously undervalued. Their presence in music from back then is almost ubiquitous.
In one of life’s vagaries, she and her singers, and Cramer, recorded a song as a lark at the end of a day’s session for Buddy Killen (who worked with many artists in Nashville, including Elvis Presley). He had written a song, and they quickly laid it down for fun as a favor.
It ended up a Top-Ten hit in January 1960, by a group called The Little Dippers. The label wanted a tour. The problem was there was no such band: They were all studio musicians. So they created a substitute quartet to do the actual touring.