For years, the singer has been telling her Hong Kong fans that she wants to perform in the city, but had never delivered – and industry rumours had said the city’s venues were too small to accommodate her. During an interview to promote the 2005 release of Confessions on a Dance Floor, she even asked me: “Do people in China and the rest of the region want me to come there? How would I know? Nobody has written me any letters.”

In person, Madonna is, by turns, friendly, flippant, off the cuff and guarded. “She can smell fear like a dog,” one journalist said after an encounter. “If you know your stuff, she doesn’t mess with you,” said another. And it’s true. Those who stick to the music and reveal an inquisitiveness about songwriting and her collaborative processes are treated with a forthrightness and revealing insights. On the other hand, as one French journalist learned after criticising her collaborations with producer Mirwais, she doesn’t hesitate to kick people out of the room.

In Miami, before the release of 1998’s Ray Of Light album, the somewhat anxious, guarded singer, unsure of the public response to this uncharacteristic release (which eventually won four Grammy Awards), told me that she was going through a journey with a lot of “spiritual growth”. There were also internal struggles with the concept of fame. “People associate fame with happiness and being loved,” she said. “Even I made that mistake at the beginning. The things you hold onto the longest are the things you can walk away from.”

With all that has happened in her career since, that seems like a lifetime ago. She got married and divorced, had two kids (Lourdes and Rocco), adopted two more from Malawi (David Ritchie and Mercy James), starred in a few films (including the mega bomb Swept Away) and has become embroiled in a public custody battle over her son, Rocco, and endured speculation over a reconciliation with a former husband, actor Sean Penn.

Of course, she’s also released several albums, culminating in her most recent, Rebel Heart, a raunchy, unapologetic work that features collaborations with Kanye West, Avicii and Diplo which was an attempt by the singer to sound as current as they come. Though well reviewed and a chart topper in several countries, it also suffered drastically from an online leak before the official release.

And she’s also loosened up a bit the press. “Want some popcorn?” she casually asks me before an interview in London. With a flourish, and the attitude of a big sister settling in for a chat, she agrees to answer anything candidly – as long as it is about her music. “Let’s go!” she exclaims.

“Being famous?” she responds while thinking carefully about the answer. “In the beginning it’s a rush. You don’t know what you’re in for. You say and do things and you don’t really care. And then you go through the ‘Oh my God’ phase and you have no privacy. You become very bitter about it and want to tell everyone to f*** off. But now I’ve come out the other side and I’ve come to accept it. Where my early songs were about having a good time, the songs I write now are about the lessons I’ve learnt.”

During another candid moment, she reveals that she has had fantasies about leaving the entertainment industry. But she recognises that her position gives her a platform to say what she wants to say. To that end, she is never far from her journals, which will surely be in great demand from publishers one day. “I carry journals with me everywhere, so it’s a constant work in progress,” she says. “I try to keep working with interesting people. People who are hungry. People who are curious. People who aren’t jaded. I like to find collaborators who feel the same way.”

And over the years, there have been many successful collaborations. Since the beginning, such musical partnerships have helped her capture the current musical zeitgeist, whether it’s the dance-pop of the 1980s she made with John “Jellybean” Benitez, the darker electronica created in the 1990s with William Orbit, or the recent sessions with Diplo and others that led to the birth of Rebel Heart. This ability to repackage sounds from the underground for a mainstream audience has had a tremendous impact on the musical landscape, so it’s perhaps understandable why she becomes frustrated by the focus on her personal life.

SEE ALSO: Madonna’s Rebel Heart tour: Pole-dancing transvestite nuns, armoured dancers and 30 years of hits

A quick YouTube search uncovers Madonna’s recent onstage tribute to David Bowie, during which she performed Rebel Rebel. It comes as no surprise to learn that Bowie, who died this month from cancer, was one of the first performers she saw live and who first inspired her as an artist. I can’t remember if it was David Bowie or Elton John who I saw first,” she says thoughtfully. “But I was punished for both of them. I wouldn’t have turned out the way I was if I didn’t have those old-fashioned values to rebel against.”

And with a grin, she awaits the next question. The hard exterior has been broken down, and now she’s just a person talking about music. A person, however, who has changed the world’s music and cultural landscapes, the perception of women in pop and beyond, who has smashed taboos about what can be performed on stage, and who has had an untold influence on several generations of would be musicians.

“So when is the book coming out?”

“Oh,” she chuckles. “Not until I’m 80.”

Then, she goes on to explain that there’s so much more to do and accomplish. She is, after all, Madonna.

Madonna, Feb 17-18, 8pm, AsiaWorld-Arena, Hong Kong International Airport; Feb 20-21, 8pm, Event Centre, Studio City, Cotai Strip, Macau. All shows sold out