Mr. Davis was born Ellis CeDell Davis in Helena, Ark., on June 9, 1926, though some sources say it was 1927. His mother was known as a faith healer, and his father ran a juke joint. Although his mother thought the blues was devil’s music, he took to the style early, starting on diddley-bow, a one-stringed instrument made by nailing a wire to a wall. He moved on to harmonica and guitar, often sneaking into juke joints to listen to music.

He contracted polio when he was 10, leaving him with partly paralyzed arms and legs and requiring crutches to walk. But he was determined to stay with music. He told Mr. Palmer: “I was right-handed, but I couldn’t use my right hand, so I had to turn my guitar around. I play left-handed now. But I still needed something to slide with, and my mother had these knives, a set of silverware, and I kind of swiped one of them.”

He reinvented his playing using the handle of a table knife. “Almost everything that you could do with your hands, I could do it with the knife,” he told David Ramsey this year in the magazine The Oxford American. “It’s all in the way you handle it. Drag, slide, push it up and down.”

As a teenager, Mr. Davis played street corners and juke joints around Helena, which at the time was a bustling Mississippi River port, “wide open” with gamblers, bootleggers and honky-tonks, Mr. Davis recalled in the 1984 documentary “Blues Back Home.”

There he met some of the era’s leading blues musicians and started appearing on two live blues radio shows on KFFA in Helena: “King Biscuit Time” with Sonny Boy Williamson and “Bright Star Flour” with Robert Nighthawk, a fellow slide guitarist. From 1953 to 1963, he and Mr. Nighthawk performed together, and they moved for a time to St. Louis.