A spokesman for Tillis, Don Murry Grubbs, said Tillis died early Sunday at Munroe Regional Medical Center in Ocala, Florida. He had a couple of top 10 hits in the 1960s before reaching the top of the charts throughout the "70s".
His first big hit as a songwriter was "I'm exhausted", which was recorded that same year by Webb Pierce, who went on to record several more of Tillis's compositions.
Tillis appeared on several television shows, including "Hee Haw" and "Hollywood Squares".
He penned the song Coca Cola Cowboy for Clint Eastwood flick Every Which Way but Loose.
Tillis, born Lonnie Melvin Tillis, grew up in Florida and developed a stutter that would stay with him throughout his life as a result of an early bout of malaria; the stutter did not affect his singing voice.More news: San Diego County unemployment drops to 3.7% but job growth stalls
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"After a lot of years and more hurting than I like to remember, I can talk about it lightly - which eases things a bit", he wrote in "Stutterin' Boy", his 1984 autobiography.
Additionally, Tillis had other hits such as Stateside, I Got the Hoss, Send Me Down to Tucson, Neon Rose, Sawmill and Midnight, Me and the Blues.
The Country Music Hall of Famer leaves behind six children (Pam Tillis, Connie Tillis, Cindy Shorey, Sonny Tillis, Carrie April Tillis, and Hannah Puryear), six grandchildren, a great grandson, a sister (Linda Crosby) and brother (Richard Tillis), the mother of five of his children (Doris Tillis), and his longtime partner (Kathy DeMonaco). It wasn't a commercial success, but the group was nominated for vocal event of the year by the Country Music Association.
"I'm just so thankful, for everything", he said when he was inducted. He received his award in February 2012 during a White House ceremony.