Odetta: Inspirational singer of American folk music who lent her voice to the civil-rights movement

When Barack Obama won the US presidential election last month, he had no doubts about who he wanted to sing at his inauguration. By then confined to a wheelchair and fighting heart disease, Odetta – an ardent Obama supporter indelibly associated with musical protest and the civil-rights battles of old – was determined to perform and play her own part in the unfolding of history. Sadly she didn't make it, but her mountainous voice and intensely emotional delivery had a profound impact and formative influence on everyone from Janis Joplin to Bob Dylan and Bruce Springsteen, and her folk, blues and spiritual music legacy is immense.

She was fêted by Bill Clinton (who presented her with a National Medal of the Arts in 1999), and Martin Luther King once called her "the queen of American folk song" although Odetta herself – classically trained and renowned for her mastery of a variety of styles – refuted the tag. "I'm not a real folk singer," she said. "I'm a musical historian. I'm a city kid who has admired an area and who got into it. I've been fortunate with folk music. I can do my teaching and preaching, my propagandising."

She was born Odetta Holmes, to a struggling family in Birmingham, Alabama during the depths of the Depression, on New Year's Eve, 1930. Her father, Reuben, died soon after her birth and her mother Flora, a maid, subsequently married a janitor called Zadock Felious, and the family moved to Los Angeles when Odetta was six. Odetta took her stepfather's surname while she was growing up, but her professional name was always simply "Odetta".

The musical talents she'd already displayed on her grandmother's piano took firmer root in LA where, encouraged by her stepfather, she was enthused by seeing the Nat King Cole trio, Ella Fitzgerald, Count Basie and Jimmy Rushing. She took singing lessons, studied opera at Belmont High School and worked as a cleaner while furthering her classical music education with night classes at LA City College. She was moulded as a soprano, but rebelled after joining the chorus line in a West Coast production of Finian's Rainbow. The show wound up in San Francisco, where she found herself drawn to the bohemian coffee houses where she hung out with the guitarists and beatniks who represented the emergent folk scene there.

She was offered a slot singing at the hungry i club in San Francisco and her expressive, towering voice and powerful personality won her instant acclaim. She incorporated America's folk and blues tradition into her own distinctive style and was booked at another San Francisco club, the Tin Angel, before moving to New York to appear at the Blue Angel.

In New York she caught the attention of the city's folk cognoscenti, notably Pete Seeger and Harry Belafonte, who was to become a lifelong friend and whose enthusiastic support helped spread her fast-growing reputation as a spectacular song interpreter. She was offered a part in the 1955 movie Cinerama Holiday, singing the sea shanty "Santy Anno", and returned to California, where she stayed for the next two years, with a season at the Turnabout Theatre in Los Angeles.

However, it was in Chicago that her career took another significant step in the wake of successful stints at the city's Gate of Horn club in the basement of the Rice Hotel. It was there she was spotted by the sharp-suited Al Grossman, who became her manager and signed her to the Tradition label, which released her first two albums, Odetta Sings Ballads and Blues (1956), which included seminal interpretations of "Muleskinner Blues" and "Jack O'Diamonds"; and Live at the Gate of Horn (1957), which included a barnstorming version of the spiritual "He's Got The Whole World In His Hands".

Odetta gained national acclaim when Harry Belafonte invited her to perform on his programme TV Tonight, resulting in a new deal with the Vanguard label and a landmark appearance at the 1960 Newport Folk Festival, where she did show-stopping performances of everything from ballads and lullabies to prison work songs and grandstanding spirituals. This in turn led to shows at New York's Carnegie Hall and another movie role in Sanctuary (1961), and Odetta began to be talked of in the same vein as some of her own heroes, folk blues greats like Bessie Smith, Leadbelly and Mahalia Jackson.

Odetta had a unique style, seeming almost to inhabit the songs she was singing, which she saw as part of her own education and understanding. "In school you learn about American history through battles, but I learned about the United States and the people of the United States through this music and the songs I sing."

Glamorous and exotic, she transfixed audiences, with her commanding frame, flamboyant dresses, large earrings, flashing eyes, engulfing smile, striking hair (she once proudly claimed to have invented the Afro hair style) and unusually expressive features. She played a wooden guitar which she called "Baby" and when she sang nobody took their eyes off her. The youthful Bob Dylan acknowledged that seeing and falling in love with Odetta was a deciding factor in swapping his electric guitar for an acoustic and embracing the joys of folk music. Odetta, in turn, championed Dylan, encouraging Al Grossman to sign him and in 1965 she recorded an album of his songs, Odetta Sings Dylan.

Unlike Dylan, however, her political conviction remained strong. She marched with Martin Luther King in Selma, Alabama in 1963 and Rosa Parks, who started the boycott of segregated buses in Montgomery, claimed to have been inspired by Odetta's singing. She became a fixture at civil-rights protest rallies, rousing the campaigners singing the old slavery anthem "O Freedom" on the Washington march to Capitol Hill in 1963, as well as singing for John F. Kennedy. "When you reach a fork in the road you can either lie down and die or insist upon your life," she said.

Odetta was a natural performer and entertainer and despite her later struggles with ill-health she continued to make records and give live shows. She embraced some modern music – performing Bruce Springsteen's "57 Channels" as a chant – and undertook a major US tour in January, as committed as ever to the social struggles which often consumed her music.

She provided a bridge between ethnic cultures and musical genres, linking traditional American blues and gospel with contemporary folk music, with a unique gift for conveying the spirit of a song, whether a rousing "We Shall Overcome", a forbidding "God's Gonna Cut You Down", Leadbelly's angry "Bourgeois Blues", a heartbreaking take on "Sometimes I Feel Like a Motherless Child" or her comedic hit duet with her good friend Harry Belafonte, "There's A Hole In My Bucket". She won numerous awards – her 2007 album Gonna Let It Shine was nominated for a Grammy – and Madeleine Peyroux, Sweet Honey in the Rock and Pete Seeger were among those who performed at a concert in her honour last year. But for Odetta, the joy of singing – and the difference she felt she could make with it – outshone all the accolades.

Odetta Holmes, singer, actress and civil-rights campaigner: born Birmingham, Alabama 31 December 1930; married three times (one son, one daughter); died New York 2 December 2008.