CALGARY - Joni Mitchell takes a long, languid haul from her cigarette, closes her eyes and exhales contentedly.

Does the iconic singer-songwriter, one of the most influential recording artists of her generation, ever feel guilty about her lifelong habit?

"Not at all," she says, taking another puff and staring intently at the burning embers. The expression on her face is so serene, her body so relaxed, you might mistake this ritual for meditation.

In her mind, it is.

"To me, tobacco is a grounding herb," she explains, as smoke swirls like a ghostly halo around blond wisps of hair twisted on the top of her head.

It's late afternoon, and we are sitting in her Calgary hotel room, talking about climate change and the "dying planet." These are the heavy themes - along with religious zealotry and "accelerated war" - that have inspired her newly recorded album and recent artwork. They are also the themes of The Fiddle and the Drum, her latest artistic collaboration, with Alberta Ballet, which opened to international fanfare in Calgary last week. The 45-minute dance, set to Mitchell's music, photo triptychs and video, is being performed in Edmonton this weekend.

Mitchell scoffs when it is suggested that the body is a microcosm of the planet, that smoking is as foolhardy and dangerous as China's addiction to coal.

"I see bodies as individual things," she says, sitting up at attention. "People who drive RVs treat me like a leper because I'm making this tiny emission that isn't going to bother them at all," says Mitchell, whose cigarette brand of choice, American Spirit, is allegedly additive-free. "Then they get in their car and drive off and leave 10,000 cartons worth of crap in the air. ... And people are quitting smoking en masse, yet cancer is still rising. Let's be realistic.

"I am a smoker. Period," she adds, jabbing the air with her cigarette.

Truth is, Mitchell doesn't know what it would be like not to smoke. When she was 7 and growing up in Saskatoon, the only child of a grocery-store manager and teacher, she was stricken with polio. The doctors didn't think she would walk again.

"I started smoking right after that," says Mitchell, now 63. "I didn't smoke to show off. I smoked alone," she says, referring to how she'd grab her bicycle and ride off into the country, finding solace in nature and a couple of butts.

"Honestly, I couldn't have gotten through life without it."

On the surface, much of Mitchell's life since then looks like that of a troubled diva. Her former manager, Elliot Roberts, has said she cancelled more concerts than she played. In the seventies, when she was riding high on the commercial popularity of such melodious hit albums as Blue and Court and Spark, she would often berate her audiences if they weren't paying close enough attention.

Later, when Mitchell felt the need to grow as an artist, she turned her back on her fans, and almost abandoned melody altogether with experimental forays into avant-garde, world and jazz music. Her progressive chord tunings and innovative harmonies are now regarded as revolutionary. But at the time, her early fans couldn't keep up.

Then, in the mid-nineties, Mitchell had a startling comeback with Turbulent Indigo, which won a Grammy Award for best pop album. She was showered with honours and inducted into the Rock and Roll Hall of Fame. Still, she categorized most of the awards as "dubious" and complained that she was still "undervalued."

Mitchell stopped writing music after 1998's Taming the Tiger was knocked by many critics for being excessively negative. She put out two more albums of rerecorded songs and jazz standards to fulfill contractual obligations. Then she retreated into her Beverly Hills home and continued painting, but rarely granted interviews. Last month, when she was inducted into the Canadian Songwriters Hall of Fame, she arrived late for the reception, said a few brief words onstage, and stayed far away from reporters.

For this story, I was told she would do two interviews on Thursday or Friday, but the exact date couldn't be confirmed. It would depend on how she felt that day. There was no telling how long she might talk. And, of course, the interview wouldn't take place until after 2 p.m.; that's when the night owl typically wakes up.

By Friday morning, the time still hadn't been confirmed. Saturday was looking better. Flights were rearranged, the hotel stay extended.

But when the moment of introduction finally came to pass, Mitchell was positively glowing, sitting at the edge of the rehearsal studio, clapping her hands so widely she looked like a bird about to take flight. A canyon-sized smile spread easily across her face. Her remarks to the dancers were warm and encouraging. And a time was set up to meet and talk the following day.

"I have a pair of tights I could cut off," Mitchell jokes with Jean Grand-Maître, Alberta Ballet's artistic director, when the three of us finally sit down together. They are planning to visit the hot springs in Banff, and she didn't pack a bathing suit. Grand-Maître is here to make sure the interview doesn't stray too far from the ballet. But we don't really stand a chance.

To begin, Mitchell turns to the planet. "For the first time in my life, I'm with it," she exclaims with a throaty laugh. "Instead of being Doomsday Joan, all the calamities I've been watching for 20 years are front-page news," she says, pointing to a story in the paper about climate change.

Environmental rot was not exactly what Grand-Maître had in mind when he proposed the dance collaboration. The dance, he suggested, would revolve around a young blond ingénue and Mitchell's early life in Canada, with a set list that leaned heavily on her early hits .

"It seems kind of light," she recalls telling Grand-Maître when he came to visit her in Los Angeles about a year ago.

At the time, Mitchell was assembling a collection of photographic images for an exhibit, Green Flag Song, at L.A.'s Lev Moross Gallery. The large chartreuse-toned triptychs were created from photographic images she began taking after she returned from her summer cabin on B.C.'s Sunshine Coast to find her flat-screen TV running on negative. "There was a black-and-white movie running in green and pink, pulsing to green and yellow, then pulsing to green and white," she explains. "I kept thinking, 'This is a magical TV set.'"

Mitchell began shooting the ghostly images, modified them digitally, and printed them onto canvas. She focused on war images, jumbling current and historic footage, and added some Busby Berkeley dancers for comic relief.

"The degenerate quality of the images was absolutely appropriate for the topic," she says, lighting up an American Spirit and launching into an impassioned monologue about the folly of spending so many resources on war when they could be used to clean up the larger "earthling" problem.

When Grand-Maître saw the new artwork, he said he wanted to use it in the ballet.

"You can't put those images with that music you've chosen," Mitchell told him. But while the new songs she had started writing - the first in nearly a decade - would have made a natural accompaniment, she had actually finished only two.

And so together they refashioned the ballet into a lament for the planet, and came up with a score largely drawn from her repertoire in the eighties and nineties. She seems to take a perverse delight in the fact that most of the songs are her least popular.

Mitchell's talk sounds tough, but her demeanour is gentle, almost vulnerable: "My later work, from my sixth album on - and I did 21 or 22 - was really underrated. Every time I did an album, it was unfavourably compared to Court and Spark. Until Blue sold more over time, then it was unfavourably compared to Blue." She laughs.

"The chords I like are complex," she adds. "They're fresh in the history of harmony. They're mostly suss [suspended] chords. It's still taught in the schools not to stay on a suss chord too long. I didn't know the term suss chord, I called them chords of inquiry. They're unresolved. So, traditionally in the laws of harmony, even at the end of the 20th century, it wasn't good to go from a suss chord to a suss chord, and not to stay on them too long. I guess it's because men like to bring that to harmonic resolution. It went against the grain of normal composition."

She pauses, staring into space, and then returns with a bang. "To enjoy my music, you need depth and emotionality. Those two traits are bred out of the white, straight males who control the press."

For a woman who marches to her own suspended chords, though, Mitchell has a curious distaste for feminism. "They're Amazons, a lot of the ones that I met," she says, leaning back and placing her frosty pink, perfectly manicured toes onto the coffee table. "In some ways, I think the movement did more harm than good. I think it created an aggressive-type female with a sense of entitlement that's a bit of a monster."

On a more personal level, Mitchell is learning late in life that it isn't all that easy to coax children onto the path you want. In 1997, she reunited with her daughter, Kilauren Gibb, the baby she put up for adoption, at 21, when she was a penniless musician. "In some ways, my gift for music and writing was born out of tragedy, really, and loss," she told the Los Angeles Times in 2004. "When my daughter returned to me, the gift kind of went with it. The songwriting was almost like something I did while I was waiting for my daughter to come back."

For 10 years, Mitchell happily retreated into domestic life. "I was being a grandmother," she says, smiling brightly. "My house was dripping in pictures of my grandchildren. I spent a few years basically puttering, and then I realized: My parents are still living; they're only 30 years older than I am. I've had a very full life, but only two-thirds of it is gone. I'm a little young for retirement."

She and her daughter are currently estranged. She has lots to say about the problems they've encountered. The stories spill out, easily and ugly. Until she suddenly remembers this is an interview.

"Can you please keep the kid out of it?" she asks, trustingly. "It will only fan the flame. Let's just say it's a work in progress."

The family rift has had one silver lining: It has opened up room for creativity to rush in. "I honestly didn't think I'd ever write again," she says wistfully.

Given the dark subject matter - war, torture, "fertile farmlands buried under subdivisions" - the music for the new songs is surprisingly bright and uplifting.

If, an adaptation of the Rudyard Kipling poem that's being used in the ballet, has a buoyant, hip-hop groove. Shine is a lush lullaby for the soul. "I always try to do that," she says of the dichotomy. "Even my saddest songs - The Beat of Black Wings, for instance - is set to a very happy pop melody. It's like the sugar coating on a bitter pill."

Her agent is now in L.A. shopping the new album around, but Mitchell still doesn't have much time for the music business. Other things seem more important. A self-described Buddhist-Gnostic hybrid, she was introduced to Buddhism through a mind-bending encounter with the Tibetan Buddhist spiritual master Chogyam Trungpa while performing on Bob Dylan's Rolling Thunder tour. It was 1975 and she was being paid in cocaine during a brief dalliance with drugs.

The monk asked her if she believed in God. "Yes," she replied, snorting a line right in front of him. "Here's my god and here is my prayer." The monk flared his nostrils and "zapped" her into an awakened state of consciousness with rhythmic breathing. For three days, she had no sense of self.

"My mind was back in Eden, the mind before the fall. With the 'I' gone, you no longer have a divisional mind that goes 'good, bad, right, wrong.'

"I am of the 'God is within' school," Mitchell adds, explaining that she sometimes gets close to re-entering a similar state, which she now calls the dazzling darkness, while painting or playing pinball.

"I see the entire world as Eden, and every time you take an inch of it away, you must do so with respect. We've just whittled it down to nothing, so that it can no longer support us. We are a disease upon its back, and it's calling on all of its immune system to get us off."

And God doesn't mind the tobacco smoke in them thar gardens?

"Look," she says laughing. "I smoked in cars, in saunas, in all sorts of small spaces. If secondary smoke is going to kill me, I would have been dead 20 years ago."