Earl Scruggs and the late Lester Flatt are now members of the Nashville Songwriters Hall of Fame.
Flatt & Scruggs teamed as a bluegrass act in the 1940s. They recorded the theme song to "The Beverly Hillbillies" TV show in 1962, and their instrumental "Foggy Mountain Breakdown" was used in the 1967 film "Bonnie and Clyde."
The duo broke up in 1969 amid a dispute over whether they should try incorporating other styles of music, as Scruggs wanted, or stick to tradition. Flatt died in 1979.
"All songs don't have to have words," said Marty Stuart in introducing Scruggs, 83, at Sunday's induction ceremony. "Some things are better left unsaid. With his fingers on the banjo, Earl provided a platform for the sounds they had going."
Hank Williams Jr., gospel singer Dottie Rambo, and country tunesmiths Bob DiPiero and Mac McAnally were also inducted.
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Williams, 58, is the son of Hank Williams Sr., who was inducted in the hall of fame's charter group of 1970. Hits by the younger Williams include "Family Tradition" and "Texas Women."
"People sometimes think of my grandfather as a songwriter and my dad as a performer," said daughter Holly Williams. "But dad can cut to the heart in his songs."
Hall member Jimmy Buffett introduced McAnally, who also plays in Buffett's Coral Reefer Band. McAnally's hits include "Old Flame" and "All These Years."
"I Go to the Rock," one of Rambo's best-known songs, was recorded by Whitney Houston for her 1996 movie, "The Preacher's Wife."
DiPiero wrote the hits "Blue Clear Sky" and "Wink."