In a recording career that has spanned 20 years and 15 albums and has ventured into pop, folk and jazz - including a collaboration with the great bassist Charlie Mingus - Joni Mitchell has earned a reputation as a literate and musically adventurous artist.
But "major cultural figure of the last half of the twentieth century?" "Prophet?" Mitchell pauses to contemplate the mantles thrust in her direction at a press conference this week in Toronto. A querulous smile crosses her angular face (the most prominent angle formed by that unforgettable overbite). After looking around, as if for someone to save her, Mitchell protests gently, "I don't think that it would be healthy to think of yourself that way. Bob Dylan may be a major cultural figure. I think of my role, as I put in a song once - 'chicken scratching for my immortality.' "
Noted for her impatience with interviews and interviewers, Mitchell, 44, seems relaxed and amiable as she sips coffee, smokes cigarettes and answers questions about her new album, Chalk Mark in a Rain Storm. She talks about a career that has encompassed the Toronto folk scene ("everybody had songs they were identified with…hands-off songs…eventually you had to write your own"), hanging out - a naïve youngster from the Prairies - with Crosby, Stills, Nash and Young in California ("They were going to call their first album The Frozen Noses. I didn't know what that meant"), and collaborations with partners ranging from Mingus to L.A. sax player Tom Scott and the synth-whiz Thomas Dolby.
Mitchell's influence on others has also been considerable and diverse: her 1975 album The Hissing of summer Lawns is said to be a favourite of Prince's; her journey from folk to more idiosyncratic musical pastures has been echoed in the career of Jane Sibbery; the influence of her early material can be seen in the work of modern urban folkies such as Suzanne Vega.
Chalk Mark is her most ambitious collaboration to date, featuring a cast that includes Peter Gabriel, Willie Nelson, former Eagle Don Henley, former Car Ben Orr, sax player Wayne Shorter and - to the surprise of many - Billy Idol and his guitarist Steve Stevens.
Mitchell doesn't think her host of co-stars remarkable: "I just did what I always do: you run into someone at the coffee machine in the studio and you ask what they're doing; that's how most of the people got involved. I called Willie Nelson and Billy Idol.
"I cast voices just like I would cast faces for a film."
Recorded in a number of studios in Britain and the United States, Chalk Mark began at Gabriel's Ashcombe House studio in Bath in 1986. While Mitchell was locked in the studio - she insisted on setting the direction for the album before anyone, even husband and co-producer Larry Klein, could "cross the threshold" - the world outside was in turmoil. A radioactive cloud from the Chernobyl reactor was floating over Northern Europe. Across the valley from Gabriel's studio was the airfield from which the United States launched its bombing raid on Libya.
"We were so close we could see the orange light from the runway," Mitchell recalls. "And we realized that that if there was going to be any retaliation we might be affected. All our thinking turned to war; the globe seemed so small and we seemed so fragile. You realize that nothing is 'way over there.' "
That sense of a fragile world is carried through in Chalk Mark's topical songs. Although there's nothing quite as blunt as Tax Free, a pointed attack on TV evangelists from her 1985 album Dog Eat Dog, Mitchell has included a couple of songs set against the backdrop of war - The Tea Leaf Prophecy (Lay Down Your Arms), which takes place in the Second World War and The Beat of Black Wings, the story of Killer Kyle, a bitter Vietnam vet. She also takes a few shots at her ambitious contemporaries in songs such as Number One, Snakes and Ladders and The Reoccurring Dream.
Asked about the "negative" tone of her recent albums, Mitchell says she's been misunderstood. "I think there's a lot of black humour and love of language, but a lot of it is trying to be a witness to my times. We live in troubled times - perhaps we differ in how we look at it. I think of what I do as neutral reporting - I'm telling a story which is neither negative or positive; I'm not passing judgment.
"The last album was perceived as negative, but I think it was quite realistic. Now the seeds are up out of the ground and songs about the corruption of evangelists and the corruption of government, once perceived as negative, now seem like common sense."