Joni Mitchell and Joan Baez may have strummed their way through the golden age of the peaceniks, preaching love and tolerance, but it seems that, behind the scenes, the sisterhood of the flower power era was riven by more base instincts.

Mitchell, 64, has revealed the extent of the ill-feeling between her and Baez, the one-time muse and lover of Bob Dylan, as they competed for primacy as the leading female balladeer of their generation against a background of the protest movements of the 1960s and 1970s.

In an interview with Mojo magazine, Mitchell, who abandoned music in 2002 to pursue a life as a painter before returning to songwriting last year and releasing an album, said she believed Baez "would have broken my leg" if the pair had fallen out while sharing a stage.

The two women performed together in several concerts in 1975 as part of the Rolling Thunder Revue organised by Dylan and filmed by the playwright and director Sam Shepard. Mitchell and Baez, who has continued to perform for nearly 50 years and released more than 30 albums, were photographed laughing and hugging each other on stage during the tour.

But Mitchell, the daughter of a Canadian air force officer who started her career busking in Toronto, said an intense competitiveness was felt by many female artists of the era, including Janis Joplin, the drug-addicted hellraiser who electrified audiences with her rasping blues, and Laura Nyro, another member of the circle of highly acclaimed women singers led by Mitchell and Baez.

Mitchell said: "I always thought the women of song don't get along, and I don't know why that is. I had a hard time with Laura Nyro also, and Joan Baez would have broken my leg if she could, or at least that's the way it felt as a person coming out [on to the music scene]. I never felt that same sense of competition from men." She added: "[Joplin] was very competitive with me, very insecure. She was the queen of rock'n'roll one year and then Rolling Stone made me the queen of rock'n'roll and she hated me after that."

It is likely that the antipathy between Mitchell, who has a reputation for not pulling her punches when it comes to expressing her opinions  she described the music industry as a "cesspool" when she put her recording career on hold six years ago  and Baez is rooted in the certainty with which both women hold their views.

Baez once said: "I've never had a humble opinion. If you've got an opinion why be humble about it."

It is a philosophy which Mitchell continues to take to heart, expressing physical disgust at St Augustine, the American poet Anne Sexton and Sylvia Plath, the wife of Ted Hughes who took her own life, after it was suggested that her music was confessional. She said: "Augustine, Anne Sexton and Sylvia Plath are confessional writers and all three make me sick. I have nothing in common with them. Sexton was a whopping liar. She didn't even tell the truth to her shrink. All of her confessions, as far as I can determine, seem to be contrived. Plath, I don't know that well, but I don't think suicide is chic."

The singer, whose critically praised Shine album last year was released under a label owned by the Starbucks coffee chain, goes out her way to try to repair the reputation of Jimi Hendrix as a wild man of rock, recalling a conversation in which he said he regretted smashing his guitar on stage because he thought it made people think he was a violent woman beater.