Tori Amos doesn't "do" sports-casual. It may be 9am on a Sunday morning, but she's immaculately made-up and wearing a silver-grey designer dress. When I mention I've recently succumbed to reading-glasses, she gamely models several pricey-looking pairs of her own specs. Some interviewees keep their guard up, but Amos - very much the touchy-feely type - is happy to bond.
We've met in Mayfair, London, to chat about the singer's new record, Night of Hunters. A 21st-century song cycle that saw her head-hunted by the prestigious classical imprint Deutsche Grammophon, the work pairs her voice and piano with such esteemed players as the Apollon Musagète string quartet, and Andreas Ottensamer, clarinet soloist with the Berlin Philharmonic.
Exquisitely arranged and performed the album may be, but it is not for purists. A lengthy, typically ambitious affair, it sees Amos write new songs around piano themes by such luminaries as Bach, Debussy, Schubert and Mendelssohn. It was this chance to "fiddle with the masters' source material", the 48-year-old, North Carolina-born singer says, that drew her to the project in the first place.
"Sure, Clara Schumann wrote a variation or two," she explains, "but in the classical world, women have rarely been accepted as composers. I couldn't resist a project this dangerous and unusual. I couldn't turn it down for womankind."
Unlike most rock stars, Amos was classically trained. But she was turfed out of the Peabody Conservatory in Baltimore, Maryland, at age 11 after a liking for Led Zeppelin began to infiltrate her Beethoven. She acknowledges that Night of Hunters feels like a kind of poetic justice; her chance to show the stuffy set just what she is capable of.
"But I also knew the stakes were high," she adds. "If you get this wrong you can't shrug it off like a bad night at karaoke."
Time was when a singer-songwriter could "knock out" a record quite spontaneously and then tour it. But like her contemporaries Björk and PJ Harvey, Amos has nurtured a fan-base accustomed to painstaking, many-layered, conceptually rich releases. American Doll Posse, for example, saw Amos develop and inhabit five sharply contrasting female characters in 1997, while 1991's The Beekeeper was part informed by such arcane topics as apiary and the Gnostic Gospels.
Night of Hunters, too, takes a bit of unravelling, but at root its Celtic folklore and magic realism-influenced plot centres upon the troubled relationship of a present-day couple who have sailed across the Atlantic to Ireland and settled near Kinsale, County Cork.
"It's sundown and an argument has happened," says Amos. "It's been brewing for a while and the guy leaves. The rest of the story happens between dusk and dawn when this magical, shape-shifting being called Annabelle takes the main character, Tori, back to a time when she and her partner weren't turning their words against each other. As Annabelle says, every couple has a version of what they call truth."
Ah, yes, Annabelle. Sometimes fox and sometimes goose, this unorthodox marriage guidance counsellor is actually voiced by Amos's 10-year-old daughter Natashya, a precocious talent who shares lead vocals with mum on songs such as Snowblind and Cactus Practice.
"It's something we've done since she was very little," says Amos, of singing with her daughter. "When we're away at the beach house in Florida, Tash and I will gather around the Bösendorfer and trade off. She sees herself as an actor, first. An actor who found the blues when she was nine. The challenge for me was to try and understand her instrument and incorporate that in to the song-cycle."
So she and Tash's father (Amos's English-born husband and sound-engineer Mark Hawley) didn't have any misgivings about involving their daughter in something so demanding?
"No, because it was something Tash really wanted to do, and she's starting at The Sylvia Young Theatre School [London] in the fall. She's travelled with us on six world tours, but it's important that she has the chance to develop her own life now and she won't be going on the road with us this time. When you're away for six months, it can be hard to integrate when you get back. Friendships are made without you, you know?'"
Given that Amos's 19-year-old niece Kelsey Dobyns also sings on Night of Hunters (she plays the Fire Muse on the title track), it is very much a family affair. Factor that Amos actually owns a Georgian house near Kinsale, County Cork, moreover, and you can't help but wonder whether her song-cycle harbours some home truths. Might the romantically challenged couple in the story actually be Hawley and Amos herself, I ask?
"Mark said: 'The press will have us divorced after the first week's promo!'" says Amos. "But the truth is, I'm crazy about him. We've weathered a lot of storms and outside forces, but we've been together 16 years. Things seem to be happening so fast in the world. Traumatic things. And without going into detail, Mark and I are now at that age when we have to be the responsible ones when someone in the family is in crisis. I couldn't have written songs like Your Ghost and Edge of the Moon without us going through a lot together, but we're great."
Next year sees the 20th anniversary of Little Earthquakes, the debut album that put Amos on the map. Night of Hunters aside, though, her other main focus right now is a collaboration with playwright Samuel Adamson on a stage musical adaptation of George McDonald's 19th-century fairy tale The Light Princess, due to open at the National Theatre, London, in 2012. It's a fitting project for Amos, once dubbed "Queen of the Fairies" to take on, but McDonald's fantastical allegory has an enduring resonance, the princess's "lightness" a vehicle for Amos to comment upon modern-day illnesses such as anorexia.
"One of our directors, Nicholas Hytner told me, 'Tori, a musical is a glorious nightmare!'" says the singer of her undertaking. "I'm learning a lot, but I have to say it's the hardest thing I've ever done. The casting process was so tough that I wanted Tash to rethink her career choice. I don't know how people deal with the rejection, actually. It would be soul-destroying for me."
Night of Hunters is out on Deutsche Grammophon