In the pantheon of great soul singers, Aretha Franklin may have been known as "the queen", but Nina Simone was always the "high priestess". But she was also a jazz and blues singer, and came from a proud tradition of black female American singers who traced their lineage back to Bessie Smith and Billie Holiday.

One of the most distinctive voices of the latter half of the 20th century, she was capable as a live performer of spine-chilling intensity. She also displayed a wayward unpredictability, but this only served to heighten her artistic mystique.

One of eight children, she was born Eunice Kathleen Waymon at Tryon in North Carolina. By the age of seven she was playing piano and organ and singing with her sisters in the church choir. But the racial prejudice that was endemic in the deep South of the 1940s had an early and lasting effect upon her. Years later she described as the formative event of her life a piano recital she gave in the local library at the age of 12 at which her parents were asked to stand at the back because they were black.

With the financial support of the local black community, which shared a collective pride in her precocious talent, she was sent to a girl's boarding school and then to the Juilliard School of Music in New York. Her classical training came to an abrupt halt at 21, however, when she was refused a scholarship by the Curtis School of Music in Philadelphia. For the rest of her life she believed this was due to her race.

Out of necessity she took an engagement at the Midtown Bar and Grill, Atlantic City in July 1954. On the first night she played classical and gospel selections on the piano without once opening her mouth. The following night Harry Seward, the club owner, told her that either she sang or she was out of a job. She began a reluctant singing career and three years later she was performing jazz and blues at Carnegie Hall. "I'm where you always wanted me to be but I'm not playing Bach," she wrote to her parents.

Her first album, in 1958, was a phenomenal debut, including "I Loves You, Porgy", her first million seller, and "My Baby Just Cares For Me". Ranging across gospel, jazz, blues and cabaret standards, she worked for several labels until she switched in 1963 to Philips, which was run by her longtime friend and mentor, Willy Langenberg. Seven albums of near genius followed in a prolific four years and it was during this period that she recorded some of her angriest and best songs , including "Old Jim Crow" and "Mississippi Goddam", which became virtually a civil rights anthem.

There was also a spine-tingling version of Billie Holiday's "Strange Fruit", a song she later stopped singing because it upset her too much.

At the same time she also developed into a powerful writer, as witnessed by the remarkable "Four Women", a mini-novel in song, painting powerful portraits of four black women of different backgrounds and generations.

She was a close was a close friend and ally of both Malcolm X and Dr Martin Luther King, and sang "We Shall Overcome" at King's side on many of the great civil rights marches of the 1960s. Souvenirs of both men continued to hold pride of place in the living room of her home in the south of France until her death.

She left America at the end of the 1960s, claiming that both the FBI and the CIA had files on her and she could no longer stand the racism. At the time of this self-imposed exile, she was enjoying the most commercially successful period of her career, with big pop crossover hits such as "Ain't Got No -- I Got Life", from the musical "Hair", and a cover of the Bee Gees' "To Love Somebody".

For the next 25 years she moved restlessly around the globe, living in Barbados, Liberia, Egypt, Turkey, Holland and Switzerland before she finally settled in Aix-en-Provence in 1994. It was the first house she had ever owned.

After she left America, albums continued to appear sporadically, the best of them being "Baltimore" in 1978. But she missed playing live (even though she was capable of insulting and abusing her audience when she did) and during the 1980s she began touring again. When Chanel appropriated "My Baby Just Cares for Me" for a television advert, a new generation discovered her music and she became an icon of late-Eighties jazz cool.

She married twice and had one daughter but she led a troubled personal life. She suffered four miscarriages and had difficult relationships with a string of powerful and often violent men. In her autobiography, "I Put a Spell on You", she recounted how she was beaten by her manager and husband Andrew Stroud. There was also an affair with Earl Barrow, the Prime Minister of Barbados. Then in Liberia, where she lived for four years in the late Seventies, she was assaulted and hurt so badly by the man she was living with that she had to go to hospital.

She next became engaged to C. C. Dennis, a prominent local politician, with equally unhappy consequences. When she was out of the country Dennis married someone else -- and he was killed by an assassin's bullet during the 1980 coup.

She was volatile and highly-strung, and her artistic career was littered with no-shows, walk-outs, fights and tantrums. "If you're a black woman and you stand up for yourself people say you're difficult," she said when asked about her reputation. But the stories about her were manifold. She once cancelled a London concert without notice because she was "distressed" over an injury to her dog. It was reported in 1988 that she had closed a business meeting by pulling a knife, and in 1996 she was given a suspended sentence by French magistrates for firing an air-rifle at two boys playing in the swimming pool of a neighbouring villa. She claimed they were making too much noise.

She had suffered from ill-health for several years and employed a live-in nurse. But she continued to perform, last appearing in Britain in August 2001 at the Bishopstock Festival. By then, she freely admitted she was only doing it for the money, but she was still guaranteed a rapturous reception wherever she played.

She is survived by her daughter.

Nina Simone, singer, was born on February 21, 1933. She died on April 20, 2003, aged 70.