Behind the high fence on an anonymous Rangoon road, an old colonial house sits in slightly faded grandeur. Somewhere inside Aung San Suu Kyi is playing the piano. It is a daily ritual, developed while spending most of the past 21 years in detention as the leader of the movement to bring democracy to military-ruled Burma.
"During my years of house arrest I've often wished that I were a composer because then I could have spent my time composing," she says. "Music is much more universal than words."
It is also a way to assert her freedom in the face of her captors, who, despite making a great show of lifting her house arrest after widely discredited elections last November, continue to monitor her communications and travel, so that she rarely leaves the house except to visit the offices of her political party, the National League for Democracy (NLD).
"I don't feel any freer," she explains. "Because I never felt unfree. I never felt I was not free in all these years, so the fact that I am no longer under house arrest does not make me feel any freer." She adds, with a smile, "I am a lot busier."
Today she is busy because she has agreed to meet me and two colleagues commissioned by the rock band U2 to shoot a short film for their world tour. By the time U2, who headline the Glastonbury Festival this Friday, finish their 3600 Tour next month, seven million people will have seen them play in 30 countries. If any are unfamiliar with Burma or its Nobel laureate, by the time the band perform their hit song "Walk On", written for her, they will know who she is and what she stands for. Many will sign up to join Amnesty International or the Free Burma Campaign.
When Aung San Suu Kyi's house arrest was lifted, it was Bono's idea secretly to shoot a film to promote the cause of the thousands of prisoners of conscience who remain in Burmese jails. Like something from a spy novel, a covert line of communication was set up, and after several false starts we flew into Thailand to fill our cameras with holiday shots for our "cover story". Securing tourist visas in Bangkok, we took off for Rangoon, where our mobiles no longer work, where emails are monitored and caution is advised in case "someone is watching".
The NLD, led by Aung San Suu Kyi, won 82 per cent of the seats in the 1990 elections, but the military has always refused to transfer power. After decades of dictatorship, the country has become the poorest in south-east Asia and also the most paranoid – there are countless stories of people being arrested for saying the wrong thing in the wrong place.
As Aung San Suu Kyi's communications are censored and often fail to arrive, it wasn't entirely surprising that at the gate to her house the duty team was not expecting us ... and were unfamiliar with the U2 back catalogue. Fortunately, our credentials were rapidly established and a makeshift studio set up in the living room, including a green bedsheet taped to the wall to create a "green screen", for post-production graphics.
"After many years, I am finally able to speak to you." Fluent, articulate and graceful, Daw Suu, as everyone calls her, is a natural and charismatic presence in front of the camera, retaining her striking good looks in her 66th year.
"You who across such distances sent support to Burma, we thank you. Students, teachers, workers, mothers, fathers, sisters, brothers, music fans – U2 fans like me. When you raise your voices we hear them, they are louder than any rock band, than any army."
An hour later, filming done, she sits beneath a huge screen print of her father, General Aung San, the man who led Burma to independence before being assassinated in 1947, when she was just two years old. She is encouraged to hear news of the popular uprisings in North Africa. "When I see people in the Arab countries doing the same kind of things that our young people did in 1988, showing the same kind of needs and the same kind of courage and determination to change their lives, then I feel that we are all one, and this warms my heart."
It was in 1988 that she arrived back in Burma to visit her sick mother, leaving her British husband and two children in the UK. She never returned, realising she had to stand alongside the saffron-clad monks as they led thousands of ordinary people trying to overthrow the military. Three thousand protesters were killed and 10,000 imprisoned, and despite further popular uprisings, notably in 2007, the generals still retain their grip on power.
"We have to work for change all the time," she says. "There may be times when we feel that what we have done has not really achieved great results, sometimes there may be regressions, but that doesn't matter. The world is not a static place, it shouldn't be static.
"We should be moving all the time, moving to bring about better change, instead of just sitting there and letting things happen the way other people who are not so desirous of good change wish them to happen."
No one alive today is a more recognisable symbol of peaceful resistance in the face of obdurate tyranny, and her passion for non-violent revolution is the more remarkable given the suffering of the Burmese people and the imprisonment of so many pro-democracy leaders. But her luminous conviction that working for the common good is our best calling is undimmed by any passing doubts. She wishes younger people were more politically active, even if some consider it "rather boring".
"I don't think it's boring to work for other people. I don't think its boring to think about how you might improve the lives of other people. I don't think altruism is boring. I don't think faith in freedom is boring. I would like young people to understand that: that these things are not boring at all, that these are the things that make this world the kind of place where you can shape your own destiny.'
She shaped her own destiny most profoundly when she defiantly chose not to leave Burma, knowing she would not have been allowed to return if she did. It makes her uniquely qualified to talk about freedom, the subject of her two Reith Lectures, recorded by a BBC team on a subsequent clandestine mission. Broadcast later this month, they explore how freedom can be won in her own country and what it means for the Arab Spring. In conversation, it is evident that she chooses gracefully to evade the categories imposed upon her by her captors.
"I have tried to explain to people who ask about how very constrained we feel in Burma," she says. "I always say that we feel free, those of us who have followed our own conscience – that is the greatest freedom.
"We don't think we will fail and we are not afraid of trying. The effort in itself is a triumph, the fact that we've been going on for more than 20 years, that many of our people have gone through such terrible times and yet we are still doing it, we are continuing. That in itself is a triumph, a triumph of the spirit."
And freedom will not be long coming to Burma, she predicts, inviting U2 to visit and perform "a great big concert to celebrate democracy". Musicians and artists are powerful agents for social change, a point dramatically underlined when another NLD activist, Htin Kyaw, interrupts in halting English, to recall his own 14-year imprisonment. In 2004 his wife smuggled a copy of Time magazine to him, which featured a story about U2 and "Walk On". "I was so pleased and I shed my tears," he says, eyes welling up. "I asked my younger daughter to send the lyrics in writing, but I don't know the notes so I do not sing ... but still we are walking on!"
One of the sayings for which Aung San Suu Kyi is most famous is her exhortation to "use your freedom to promote ours". Struck by Htin Kyaw's story, her face lights up in explaining that those in the West who campaign for freedom rarely realise the power they wield.
"You don't know how much it means when [people] are cut off from the rest of the world, when they have this sense that really they are still remembered, that people know that they are there."
In her youth, she laughs, all celebrities had to do was "have themselves talked about in the gossip columns". Today, she senses they understand that they can harness their fame for good.
"Bono is one of the people who really started this movement of artists getting involved in human rights issues and political issues, which is very good. I really think that he is at the head of this movement, and that now more and more artists and singers are getting involved in humanitarian concerns. Music and art in general have the power to change people, and people have the power to change history. I think that's how it goes."
With multiple copies made of our recordings and various obscure hiding places identified to get them out of the house and then the country, we come to the end of our conversation. Our practical inconveniences are trivial next to the ongoing trials of the people of Burma, and she is keen to underline the solidarity she shares with all who work for freedom. She points to the other NLD members now returning her living room to its conventional use.
"Most of the people around here have spent time in prison," she says. "But, well, here they are. That in itself is a triumph."