Odetta, the folk singer with the powerful voice who moved audiences and influenced fellow musicians for a half-century, has died. She was 77. Odetta died Tuesday of heart disease at Lenox Hill Hospital, said her manager of 12 years, Doug Yeager. She was admitted to the hospital with kidney failure about three weeks ago, he said. In spite of failing health that caused her to use a wheelchair, Odetta performed 60 concerts in the last two years, singing for 90 minutes at a time. Her singing ability never diminished, Yeager said. “The power would just come out of her like people wouldn’t believe,” he said. With her booming, classically trained voice and spare guitar, Odetta gave life to the songs by workingmen and slaves, farmers and miners, housewives and washerwomen, blacks and whites. First coming to prominence in the 1950s, she influenced Harry Belafonte, Bob Dylan, Joan Baez and other singers who had roots in the folk music boom.