Doc Watson, the guitarist and folk singer whose flat-picking style elevated the acoustic guitar to solo status in bluegrass and country music, and whose interpretations of traditional American music profoundly influenced generations of folk and rock guitarists, died on Tuesday in Winston-Salem, N.C. He was 89.

Mr. Watson, who had been blind since he was a baby, died in a hospital after recently undergoing abdominal surgery, The Associated Press quoted a hospital spokesman as saying. On Thursday his daughter, Nancy Ellen Watson, said he had been hospitalized after falling at his home in Deep Gap, N.C., adding that he did not break any bones but was very ill.

Mr. Watson, who came to national attention during the folk music revival of the early 1960s, injected a note of authenticity into a movement awash in protest songs and bland renditions of traditional tunes. In a sweetly resonant, slightly husky baritone, he sang old hymns, ballads and country blues he had learned growing up in the northwestern corner of North Carolina, which has produced fiddlers, banjo pickers and folk singers for generations.

His mountain music came as a revelation to the folk audience, as did his virtuoso guitar playing. Unlike most country and bluegrass musicians, who thought of the guitar as a secondary instrument for providing rhythmic backup, Mr. Watson executed the kind of flashy, rapid-fire melodies normally played by a fiddle or a banjo. His style influenced a generation of young musicians learning to play the guitar as folk music achieved national popularity.