It’s peculiar how retirement takes some operatic divas after the final curtain falls. After wasting her time and passion on Aristotle Onassis, and blowing those obsidian soprano tones - and surgical bel canto attack - in the last shocking period of a once epic career, Maria Callas spent her final days as a virtual recluse in the gilded cage of her Paris apartment. She died of a heart attack in 1977 at the age of 53, a tragic heroine in the (soap) opera of her own life.

That other bel canto goddess, La Stupenda Joan Sutherland, Australia’s most dramatic coloratura soprano, returned home to bow out with a memorable Marguerite de Valois in Les Huguenots at the Sydney Opera House in 1990, and then hastened to her garden in Montreux, Switzerland. She eventually dismissed even the idea of occasional teaching - “I’m 80 years old and I don’t want to have anything to do with opera anymore” - in favour of becoming a figurehead for the Cardiff Singer of the World competition; a terrible waste when so many of today’s young pretenders lack simple vocal technique and seasoned mentors who, in every sense, know the score.

Still, it could be worse. A month ago, I attended a young and upcoming British conductor’s birthday dinner and was seated opposite another diva in her supposed dotage.

Over five indifferent courses she got drunk and mortified the table by displaying her belated discovery of marijuana and single malt whiskey after three full-throttle decades of international productions, a rigid recording schedule and hour on sapping hour of practice to keep her upper register note-by-note precise. After an adulthood of unwanted celebrity and professional virtue she had embraced casual private vice, and her old profession could crash down and become the ruined fiefdom of poperatic tarts like “Katherine, Hayley and Charlotte”.

“If audiences want airbrushed and pretty-pretty over real and religiously dedicated, who am I to correct the stupid b*****ds?” she slurred. “What’s lost except a f*****g art form?”

You couldn’t really blame her, of course. Yet as the evening ground on - and on - I nevertheless found that I did.

Overture ends. Curtain up. We observe Dame Kiri Te Kanawa, perhaps the last of the Olympians, in her hotel suite in the picturesque village of Lewes, a few miles from the seaside town of Brighton, on the English coast. She is sitting pretty in a blush pink jacket and cream pants on the eve of her concert appearances in Hong Kong (on Tuesday; an invitation-only event sponsored by JP Morgan Asia Pacific) and at Singapore’s Sun Festival, where she will participate in a world exclusive performance of Peter and the Wolf, narrated by American actor Robert Redford.

Peruse your programme notes and you’ll learn that the lyric soprano of lyric sopranos stepped down from the major romantic roles that made her internationally famous back in 2004. Don’t imagine for a second, however, that this means Te Kanawa has given up on opera, be it grand, light or bouffe. It’s no coincidence that she established a foundation and trust fund in the same year. Or that unlike many such charitable enterprises it isn’t a vanity project meant to assuage an ego desperate for the identity giving heat of the suddenly absent limelight.

In fact, since 2004 her pristine image, once all graciousness, royal connections (she sang - stunningly - at Charles and Diana’s wedding) and classy sensuality with just a hint of hauteur, has been rather gleefully turned upside down by Te Kanawa herself.

She’s publicly bemoaned the poperatic idols our aforementioned inebriated deity has cravenly abandoned the field to and hasn’t minced her perfectly enunciated words. “Extraordinary snobbishness and arrogance … suffers from delusions of grandeur,” grunted one of her fellow New Zealanders only last year after she pointed out some unpalatable home truths about the country’s current crop of darling little warblers. “Opinionated,” snapped another (an odd accusation given how opinionated the entire Kiwi nation can be, not to mention evidence that prophets are still not honoured in their own homes). Then she cancelled an appearance with Australian rocker John Farnham upon discovering he liked to display the underwear his female acolytes pelted him with on stage. She won the ensuing lawsuit but her managing company still had to shell out US$100,000 in court costs. Good taste in a crude era doesn’t come cheap.

Mention her native land and stand well back: “I think I’ve sung for the New Zealand company about four times in my entire career. I couldn’t afford to sing for them more than four times! There seems to be a feeling there that I should sing for nothing. But I have to make a living. You don’t ask a doctor to operate on you for nothing, do you? If they pay you nothing, you are nothing. And it’s a small country. You can’t make a living out of opera there. That’s why the talent has to get out and train in the opera languages.”

At 64 - but looking a seriously sexy forty-something - Te Kanawa is newly liberated and clearly enjoying yielding to previously suppressed urges: “Opinionated? Well, I am opinionated. I wouldn’t have allowed myself an opinion 20 years ago because I was still ploughing through my career. I’ve … permitted myself an opinion now. I’ve had a wonderful career, I don’t have to beg and lick, I ask directly for money for the foundation and I’m hell bent, absolutely hell bent, on real singers - super singers, not instant, overnight singers - coming through. People to whom opera is a calling and a necessity, singers willing to do the tough, gradual work but who get sidestepped … by these people who are promoted beyond their abilities and are there for, oh, five minutes because someone can make a fast bundle of money off them.”

To that aim, the Kiri Te Kanawa Foundation guarantees “talented young New Zealand singers and musicians with complete dedication to their art will receive judicious and thoughtful mentoring and support to assist them in realising their dreams”. This means recipients had better have the same degree of commitment as Te Kanawa herself. Like the woman at the beginning of a certain 1980s TV series who informs her charges, “You want fame? Well, fame costs. And right here is where you start paying … with sweat,” Te Kanawa is not above drilling “my kids … my six foot Tongan, my gorgeous baritone, my American guinea pig” for seven hours straight until they get a single phrase right.

“Not a scene to lend itself to reality TV,” she says with dry wit, marking the essential difference between the efforts of ancient Art over the relative ease of modern Commerce.

So, yes, she’s mostly Mother Goose but she can be Mommie Dearest too if needed. “I will call them sometimes and say `I’m hearing things I don’t like so come on down and we’ll talk.’ One guy I called and gave a two-day talking to. He said, `I guess this is wake-up time’ and I said, `Yep, it’s time to stop running.’” Pause. Direct eye contact. “I believe in gentleness but this isn’t the gentlest of businesses. I am firm. Or as firm as I can be without doing the wagging-finger thing.”

It seems fair enough once you learn Te Kanawa began the foundation with £40,000 (HK$570,000) left to her in a will. Just when she thought she’d be unwinding she found herself checking out student recommendations from teachers, holding auditions, contacting old chums and asking for their time and expertise (for free), managing bank accounts, grant proposals, project reports, a board of executives and big corporations - Rolex, UBS and ASBank are sponsors - and hustling private donors for cash. (Tonight, she will attend a dinner hosted by JP Morgan at which students from Hong Kong’s Academy of Performing Arts [APA] will showcase their talent. Te Kanawa has been instrumental in persuading JP Morgan to sponsor a masters degree in arts management at the APA.) It is a role she plays well.

“It isn’t for me and I’m not greedy. It’s to pay for what’s needed. We keep our operating costs low, we don’t duplicate what other organisations do - and we’re practical. When I came to London years ago, I didn’t know anyone. Now we have a book of contacts and tutors so newcomers don’t face the isolation and doubt I did.”

If Te Kanawa insists on high standards, she’s also as protective as a lioness with her cubs. International opera is a tough business; prestige and millions of dollars in ticket and recording revenue are at stake. She makes time to soothe worried parents - “Well, they didn’t ask for a daughter with an amazing voice, did they?” - and checks jet-setting schedules compiled by agents who no longer care if their clients’ larynxes shrivel before their time. Agents today routinely have four or five tyro [amateur] singers on the books, so what if a couple go to the wall?

“They exploit the young ones to pay the mortgage,” Te Kanawa says with a contempt so venomous her enthusiasm instantly alters into a composed rage. “I have students and I’m seeing them suffer. I have to deal with the vocal damage because they’re straining to keep up with the work load. They’re singing on capital. They get off a long flight and they go and sing and I scream, `What are you doing? You’re mad!’ and they say, `What do I do then?’ and I say, `What’s your jet-lag time?’ and if they reply, `Five hours’ I say, `Then you take five days before you sing because your voice is just not ready - the chords are dried out.’”

Agents prove to be a hot-button topic. “There’s an agent who goes to the bottom of a bottle, there’s an agent who screws you … and an untrustworthy accountant. [They are] bumps on the road and I got over them and came out thinking positive. I can teach that too. I can’t stop anyone from making mistakes but I can make them learn from them. And from mine.”

She shrugs. “I want the next lot of singers to come through with knowledge. When my students ask, `Do I take this job or not? Who should I sign with?’ I tell them to ring me and we’ll talk about it. You have to give them a chance. Not that it isn’t always a gamble. I can hear talent but I don’t know what the psychology is. They can have the talent but do they have the brain and the stamina to go with the talent? That I can’t tell. You can just give them the opportunity.”

The diva needn’t fret. Her instincts are as excellent as her ear. Soprano Ana James, first recipient of a Kiri Te Kanawa Foundation grant, is now on the Young Artist Programme at the Royal Opera House in Convent Garden, London. Another name to watch, Auckland conductor Kerry Jago is finishing four years of study in Germany and is already sought after while Kristen Simpson is the first pianist to be granted entrance to the Summer Academy of the Solti Accademia di Bel Canto in Italy (maestro Sir Georg Solti was one of Te Kanawa’s most influential boosters). The opportunities are paying off.

Still, one wonders why it all matters quite so much to Te Kanawa. The answer possibly lies in her past. Born Claire Marie Teresa Rawstron in Gisborne, on New Zealand’s North Island, on March 6, 1944, she knew little about her birth parents except one was European and the other Maori. Her adoptive parents were Irish and Maori. In 1968, she married Desmond Park - the mining engineer became her legendarily aggressive manager despite his almost total lack of interest in opera - and adopted two children, a girl, Antonia, in 1976 and a boy, Thomas, in 1979. She divorced Park in the late 90s when she discovered he’d been having an affair. But the foundation means she’s still adopting deserving children; a therapeutic way of paying back accumulated karmic debts.

Here’s one. She may have been an established club entertainer by the age of 20 if it hadn’t been for the tyrannical Dame Sister Mary Leo yanking her out of classes for music study “in fear and trembling”. And if that hadn’t happened, who knows if Te Kanawa would have ever won the Mobil Song Quest grant that allowed her to study at the London Opera Centre and make the transition from mezzo soprano to soprano.

Here’s another. Conductor Sir Colin Davis and director John Copley ignored early reports of poor studentship from the London Opera Centre - lazy, no ambition and “meagre singing technique” was the brutal assessment - and relentlessly, ruthlessly prepared the quiet and shy girl for the part of the countess in The Marriage of Figaro. They recognised not just the voice - “Fantastically beautiful,” said Davis - but a girl willing to dream her way into the part, a backwater Cinderella who slipped into her costume and applied her make-up and believed in the character and the arc-lit fantasy heart and soul: the purest form of method acting.

By 1971 she was a star from La Scala to the Met to the Sydney Opera House and already dreaming of the day she could make her gratitude concrete.

“I had the foundation in mind right from the beginning, as soon as I got started. When you have riches, you want to give riches away, you see?”

Te Kanawa means it. Indeed, means it so much she’s considering becoming either an agent or manager to better safeguard her absolute beginners. It means so much she’s even here, with a member of the media, which she’s learned to mistrust. “The worse thing is when you’ve had a charming time, an absolutely wonderful conversation and it comes out and they’ve turned you into a monster. One article came out recently and my son rang me and said, `What the hell did you say to that woman?’ And I said, `Nothing, nothing. I thought it went really well.’ But it was an utter attack. Horrible.”

She’s faced worse, though. “I had gone out to celebrate the end of my marriage on August 30 [1997] and I got back in the morning of August 31 to find that the princess of Wales had died. I was invited to sing at Diana’s funeral but I couldn’t. Solti died and then dear Mother Teresa. That was the worst week, I will never forget that date.

“I don’t like sad. I’m not good with upset, I can’t even watch Pet Rescue without weeping.”

Perhaps, I say, it’s best to see it as another bump on a road that has yet no end in sight. “Yes,” Te Kanawa says, shoulders back in her brocade chair, brown eyes bright, blonde hair just so. “It is worth it, you know. I do need goals, challenges all the time. There’s always another mountain to climb. Climbing is hard. It’s meant to be. Otherwise what’s the point?”