But less than two weeks after wowing Edinburgh, and putting in a memorable appearance on Top of the Pops, one of music's rising stars - perhaps best known in the UK for providing the soundtrack to the Simple cleanser advertisement - has vanished; for a second time. Her management in New York do not know where she has gone, representatives of her record label in London simply shrug their shoulders and say: "Nope, we haven't a clue."
A private detective has been hired. Here was a 31-year-old American woman on the cusp of greatness, being compared to Billie Holiday and Bob Dylan as her new album Careless Love received rave reviews, and suddenly it appears she wants none of it.
It would all be rather perplexing, not to mention deeply worrying, had we not been here before. Nine years ago, Peyroux blasted on to the international scene with a coruscating debut album called Dreamland that sold 200,000 copies worldwide. Then she took off. For anyone thinking "publicity stunt" it should be pointed out that the young star did not just vanish for a few weeks. No, Peyroux walked off into the musical wilderness for eight years, abandoning almost guaranteed fame and fortune for the life of a street busker. And now it looks as if she might be trying to do it again.
How different things seemed a fortnight ago. She was energised and went down a storm in front of assembled fans in Edinburgh. Even the famously harsh festival critics were bowled over, one claiming that "90 minutes of relentlessly sensual unctuousness", had left her "feeling slightly like a pollen-drunk bee".
The singer, who had spent many of her formative years in Paris, had the critic almost believing she was in a smoky club in the Latin Quarter, as classics by Josephine Baker began to flow. "It was the performance of a star in the ascendant," came the judgement.
That summation was given further credence three days later when Peyroux appeared on the settee of BBC's Breakfast News. Everything was going right. She has not been seen since.
A week and a half later, Linda Valentine, of Universal Records, is desperately trying to track her down, although she says she does not think the singer's "life's in danger or anything like that". She said: "We had a fantastic week doing Top of the Pops and Breakfast News, but she is not an artist to revel in the exposure, far from it, so it seems she's just chosen to get away from it all. Madeleine is of the Dylan school. These are people who like to get up, play, perform, then go. They are about the music primarily. She is a musician's musician."
And while all seemed to be going famously on the British leg of the promotional tour for Careless Love there were signs that all was not well. Her only other live performance of the trip came on Saturday, 6 August, at the Shepherd's Bush Empire in London. As usual, her laid-back tones brought memories of Billie Holiday. As usual, fans were gushing in their praise of the star who has enraptured audiences across Europe and the United States.
But in the very style that has made her such a hot prospect, was a clue as to the personality that appears to want little of the glamorous life in the spotlight. One critic talked of her "fragile artistry" in an article headlined "Angel-voiced but insecure". He added: "I only wish this gifted Franco-American diva didn't seem so tense. Awkward, self-absorbed and shy at the microphone, clutching her acoustic guitar like a lifebelt."
Yet as her recording studio points out, Peyroux has never been one to revel in the trappings of fame. And the key to that would appear to be a long love affair with Paris.
Although born in small-town Georgia, and raised in Brooklyn, Paris beckoned as a 13-year-old. She moved there with her mother and quickly immersed herself in the culture of the city, if not her studies. Jazz buskers on the streets were far more appealing than school and within three years she had dropped out to join the aptly named Lost and Wandering Blues & Jazz Band.
"Playing on the acoustic streets on the Left Bank, near the Sorbonne, is such a rewarding experience," she recalled in a recent interview. "The musicians had a little bar there. We would put our instruments in the window and just hang out. The bar owner would change all the coins into paper money for us. It was a great time." But more than being fun, the period allowed her to develop as a musician in a way a more structured youth might not have done.
"I believe I was given a special chance because of the psychological freedom I had, singing in the street," she said in another interview. "If I'd stayed in school, I wouldn't have been one of those people who are encouraged to shine. I had all these transitions going on." Much better than school had been.
As with so many artists, Peyroux recalls a torrid period in her early life when she felt uncomfortable and excluded from the crowd. "I was always a little bit outside the group. It's not that I didn't appreciate Michael Jackson and Madonna. I learned all those songs by heart. But I knew I was different. I wasn't dressing like the other kids or doing the same things."
At home she was talking Greek tragedies, Plato and Socrates with her parents who were both university lecturers." I was overweight and wore second-hand clothes, so to say I was a weirdo was an understatement."
But all this time there was a rock in her life, a person who inspired and encouraged her; her father. A New Orleans-born actor (who recently died), he sat her up to watch classic television and, perhaps more importantly, introduced her to the musical stars he adored. She was encouraged to learn the guitar and the solitary performances she gave as a child have helped develop the intimate style - sometimes described as alluringly fragile - that has become a trademark.
This raw, bohemian upbringing, forged in two of the world's most creative cities was used, at least in part, to explain her talent when she first stunned jazz critics in 1996. She was greeted with a torrent of gushing reviews. Most raved about her smoke-and-whisky vocals. Others wondered how someone so young could perform classic songs by Holiday, Bessie Smith and Patsy Cline so convincingly as to make them sound her own. Time magazine pronounced the groundbreaking Dreamland "the most exciting, involving vocal performance by a new singer this year".
It was all heady stuff for the then 22-year-old, as she headlined jazz festivals and opened tours for some of the biggest names in the business. "It was great," Peyroux said. "I got to perform with fantastic musicians. I got to see Nina Simone live. I could've kept running with it, but instead I stepped back and took a breather."
That is something of an understatement. She virtually vanished, cutting ties with her record label and heading back on the road. She travelled across the States, making prolonged stops in Nashville, and hit the clubs as a journeywoman performer. Her travels even took her back busking to the streets of Paris.
They were not easy years: a cyst in her throat had to be removed, a couple of attempts at recording again came to little. Eventually, an independent label, Rounder Records, came calling and Careless Love, released in the UK by Universal, is the product. Once again the critics were raving. Once again she was described as the new Holiday, "a bittersweet, brokenhearted alto".
Yet, as Cyrus Chestnut, the acclaimed pianist who played on Dreamland, put it: "[Peyroux] has her own story to tell: with her voice, her heart, her spirit." His implication being that her life is every bit as complex and vibrant as those of the greats who have preceded her.
Peyroux, the starlet, had returned, but it quickly became apparent that the ride would be every bit as intriguing second time around. She was pencilled in to do the Parkinson show, but the performance never took place. She says she turned up to be told the gig was off.
Parkinson's people insist it was she who pulled the plug. Either way, it is another example of the quirky side of a woman clearly unwilling to compromise for a bit of publicity; she also stopped a sticker being put on her album pointing out that it was the sound of the Simple ads.
"The offers we've turned down," says Linda Valentine, sounding slightly wistful, but also deeply proud of the artist. "She is who she is and does what she does."
But Universal must simply wait and hope, like Peyroux's many fans, that this time her departure from the limelight is short-lived. She is pencilled in to play the Barbican this year, but if you want to hear her before then, it might be worth taking a trip to see which buskers are lined up in the shadow of the Sorbonne. Just in case.
Famous vanishing acts
By Louise Jack
After several years of depression, anorexia and bouts of self-mutilation, on 1 February 1995 the Manic Street Preachers guitarist checked out of his London hotel and vanished. His car was found two weeks later at the Severn Bridge and rumours of suicide abounded. Several fans claimed to have spotted him, most notably in Goa, India, but police continue to draw a blank and Edwards remains missing.
In December 1926 the 36-year-old author disappeared for 11 days. Her car was found in a chalk pit and she was eventually discovered at a hotel in Harrogate, North Yorkshire. Christie claimed to have suffered amnesia due to a nervous breakdown after the death of her mother and her husband's confession of infidelity. The 1979 film, Agatha, starring Vanessa Redgrave as Christie, is a fictionalised version of the disappearance.
On 17 February, 1995, Simon Gray's play Cell Mates opened at the Albery Theatre in London with Stephen Fry and Rik Mayall. Six days later, Fry disappeared. He was described as exhausted and possibly suffering depression. He was spotted in Belgium looking healthy. Fry said he had been suicidal and despondent, but later admitted he had behaved like a "silly old fool". The play closed on 25 March in financial trouble.
The former leader of Pink Floyd went into hiding in the early 1970s after drugs-related breakdowns and never came out. Barrett, who wrote a dozen of the band's best songs, simply turned his back on stardom. The song "Shine On You Crazy Diamond", on the band's 1975 album Wish You Were Here , is a tribute to Barrett. Today he lives a reclusive life in his home town of Cambridge, happy, on the royalties that still roll in.
The guitar genius and founder member of Fleetwood Mac left the band in 1970. He wanted them to keep only what was necessary financially and give the rest away. The band said the plan came from "a guy who took lots of acid" and Green stayed home for three years. He has suffered mental illness but in the 1980s he made three albums and helped Mick Fleetwood on his album The Visitor.