'I'm not Britney Spears, for God's sake," Diana Krall says, with the whoop of glee and incredulity she fires off at incoming bullshit. "It doesn't get in the papers if I walk the distance between my apartment and Starbucks, does it?"
Krall is on a subject that is still new to her - the transition from classy support act to million-selling jazz superstar. She used to travel with just a suitcase and some sheet music; now she's with so many make-up artists, hairdressers, gophers and technical advisers that even Diana Ross in her prime would have worried who was paying the bills.
The occasion was the London launch of Krall's latest CD, The Look of Love. It's a disc that moves her further away from the jazz keyboard prodigy she once was - towards a charismatic vocal interpreter of romantic songs. Such great jazz instrumentalists and singers as Louis Armstrong, Nat King Cole and George Benson wound up in the same place, and the record industry falls over itself to bring about these transformations.
But if the silky string arrangements, whispering bossa novas and smoky ballads sound suspiciously smooth to hardcore jazzers, Krall brings to all her work the jazz musician's instinct to personalise every beat. She still displays the subtlety of nuance and control of musical space that made a pin-drop audible in her nightclub shows. She returns classics such as Cry Me A River and I Get Along Without You Very Well to the emotions that engendered them, and her many-layered interpretations simmer with the hesitancies, abruptly glimpsed hopes, and episodes of luxuriance and resignation that characterise most lives. "It's only music. And we're only human," she says.
Krall (36) has had a lot of unwelcome attention because of her friendship with Clint Eastwood, a jazz-lover for whom she has written movie scores. "Why Dirty Harry Fell For The New Ella" was the recent headline in one British newspaper. But she is well-equipped to handle it. Stardom struck after she turned 30, with years of small-time gigging behind her. Parents, siblings, uncles and aunts have all supported Krall through her long journey, and now she can fall back on an almost year-long relationship with the scriptwriter, John-Paul Bernbach. He may think she's a class act, but the feeling is mutual. "I don't know what the hell he's doing with me," Krall says.
Krall knows plenty of buffs will sigh over the shrinking role of her piano in The Look of Love - just as they did when one of her biggest heroes, Nat King Cole, moved from jazz pianist to crooner more than half a century ago. She cites a line from the pianist, Bill Evans: "Never underestimate the layman".
"He was always aware of that," says Krall. "That's why his music was not just the most beautiful jazz but moved people everywhere, whatever their tastes. People may also not realise that I've always loved all kinds of music as well as jazz. I was rehearsing for playing with Elton John [at whose AIDS benefit] she appeared recently since I was 15."
Krall's delicate deflections of rhythm, dynamic subtlety, and controlled audacity in the pitching of notes are the outcome of years of practising with records, listening to the advice of jazz gurus, even practising opera at home with her grandmother.
But she didn't feel comfortable listening to her voice on record until the elegant 1995 standards collection, All For You. This was also one of the last Krall discs to feature prominently her deftly phrased and hard-swinging piano.
"Martha Graham used the phrase 'divine dissatisfaction' as what keeps you going," Krall says. "And of course I'm never totally satisfied with what I've done. But I don't cringe when I listen to my vocal records any more."
She erupts into hoots of laughter, an engaging habit that has resisted the recent image-grooming. Comedy played almost as big a part as music in her childhood home in a logging town in British Columbia. Straddled between Canada's British and US influences, the Kralls watched the Marx brothers, Jack Benny, Tony Hancock.
"If you grow up north of Victoria, you're very aware of both Britain and America," she says. "I got used to HP Sauce being on the table and later wondered why I couldn't get it in Boston. But I'd also be picking up on jazz on the radio from Seattle."
Krall must be one of the few thirtysomething transatlantic singing stars who can match Hancock fans line-for-line with quotes from The Blood Donor.
"Typical thing we'd do when I'd go home," Krall recalls in her affable shorthand, "was to play rummy after dinner and listen to records. My grandmother had a great voice too. My aunt Jean had been in vaudeville, my uncle Andy could sing every national anthem you could throw at him. We'd listen to everything: early American dance bands like Fred Waring's and Jean Goldkette's and lots of classical music from my dad. Creedence Clearwater Revival, choral music, Welsh choirs, hymns, Scottish music, Harry Lauder, even George Formby. George Formby!"
She suddenly breaks into I'm Leaning on a Lamp-post.
"I did a gig in Wigan in the north of England a few years ago. I didn't even know George Formby had come from Wigan, then I got to the hotel up there and it turned out to have a George Formby Room. I called my dad straight away to tell him."
Krall was a classical pianist as a child, and was still playing classical recitals in her mid-teens. But joining her high-school swing band reshaped her life. "They immediately called my mother. She thought they were calling to say I'd been misbehaving," she says. "The tutor just said, 'I want to talk to you about your daughter', and gave me Bill Evans's Waltz for Debby, and Live at the Village Vanguard. I already had Miles Davis's Kind of Blue; that was my only jazz record.
"Then I practised with records all the time - the swing of Wynton Kelly on Kind of Blue, Ahmad Jamal for the use of space, Bill Evans for harmony, some of Keith Jarrett too. It's the other side of my musical life. My piano playing comes right out of jazz grooves, but I don't think I sing from a jazz-singing point of view - more from an interpretative, storytelling point of view."
Scholarships followed, then the jazz course at Boston's Berklee College, which she abandoned when the veteran bass virtuoso, Ray Brown, took her career in hand. Brown was Ella Fitzgerald's former husband and accompanist, so he wasn't a bad judge of a singer. He advised Krall to study in Los Angeles with the pianist, Jimmy Rowles, who used to play with Billie Holiday.
Rowles described his own voice as sounding "like a canoe being dragged across a road", but he heard in Krall qualities she had not yet come to appreciate herself. It was at his suggestion that she began singing more - but as the singer/guitarist George Benson often proves, becoming a vocal star doesn't necessarily disable a powerful instrumental talent, and it's Krall's musicality that has helped her sing the unique way she does.
If anything might close the door on her jazz life, it must be the temptation to start believing her own publicity. Will the touring entourage go to her head, will the sensuous on-stage body language spill over into real life, will the knowing wistfulness of the photo-shoots get to be a habit? She's so unaffected today that the question is hard to raise.
"Just be honest. It's OK," Krall prompts.
Do you ever regret all this? Is it harder now to remember what you're in music for? Krall is briefly perplexed.
"It's been a matter of learning how to be . . . patient," she muses, half to herself. "I used to be really shy and not comfortable with that aspect of the business. I've learned to have fun with it too. In some ways those record covers represent a sense of freedom and pleasure in life I'd always felt but not always been able to express before.
"But the main thing is, it doesn't detract from your art. If I wore socks and didn't shave my legs, it would still sound the same.
"Wouldn't it?"
Diana Krall is at Dublin's Olympia Theatre on Tuesday; tickets, £32. The Look of Love is released on Verve