Shortly after settling at a table in her local village pub in Oxfordshire the Duchess of Kent is talking animatedly about “her children”. But the conversation is far removed from George, Earl of Andrews, Lady Helen Windsor and Lord Nicholas Windsor, the children of her marriage to the Duke of Kent.

No, the duchess’s mind is focused on the young people in one of the toughest areas in Hull, to whom she has been dedicating herself for almost 15 years.

The south Oxfordshire village of Brightwell Baldwin, which sits between Chalgrove and Watlington, has long been her home.

She is comfortable in this place, as is demonstrated by the cheery exchange with the bar staff, who greet her with a chorus of “Hello, Katharine”. She sings with a local choir and will tell you: “You really couldn’t find anywhere nicer to live than Brightwell Baldwin.”

But for all this, the village and the surrounding countryside will never be her spiritual home, any more than central London.

“Yorkshire is still my home,” she confesses.

Coming from the vast and rugged countryside of North Riding, she admits to sometimes “feeling a little shut in” among the neat hedgerows and narrow lanes of south Oxfordshire.

Hovingham Hall, near York, home of the Worsley family for over 400 years, was her childhood home, yet it turns out that the beautiful Ryedale countryside is of less importance to her than a corner of Hull known for its rough estates rather than parkland.

“Driving up the Holderness Road in East Hull; that is when I feel this is where I really belong,” she tells me. When she enters the school gates of Wansbeck Primary School, the duchess becomes the school teacher Mrs Kent.

For all these years the children had no clue that they were actually being taught by a member of the Royal Family. What she is known for there is her extraordinary enthusiasm for introducing music into the lives of children, who may have had precious little exposure to anything beyond The X-Factor.

“Every person loves music,” she says. But in her view it also gives confidence to children in Hull, many from deprived areas of the city, who may have few opportunities to shine or “walk tall”, while teaching music has been a powerfully emotive experience for her, shaping her own life for more than a decade. Asked about what it meant to her, she once replied: “If one in 1,000 children I ever teach jump that Berlin Wall and succeeds, it’s worth everything I’ve ever done in my life.”

The experience in Hull led her in 2004 to found a charity, Future Talent, which seeks to do for musically talented children what teaching care and motivation “did for Billy Elliot in dance”.

In a few weeks’ time, children in Oxford will be invited to bid for financial support from the charity when the city is designated as one of the charity’s ‘hot-spots’.

Her interest in music also extends to ‘grown-up’ players in Oxfordshire. The duchess is the president of the Abingdon Operatic Society, which this week is performing Anything Goes at Abingdon School, with the last performance on Saturday.

Her involvement with the society grew from her friendship with Phil Hughes, a member of the society’s committee, who also lives in Brightwell Baldwin, and the duchess now rarely misses one of the group’s shows.

Sipping cappuccino, she certainly looks younger than her 77 years, as she explains that her taste in music extends far beyond classical. She is looking forward to Cole Porter every bit as much as she anticipates the society’s autumn production of The Pirates of Penzance in October.

“Music is the most important thing in my life. The be all and end all to everything. No one in my family was particularly musical, but I was born with a love of music.”

Her father, the late Sir William Worsley, captained Yorkshire at cricket. As a schoolgirl in York she recalls dearly wishing that her father, rather than being a Yorkshire sporting hero, had instead worked in the local Rowntree’s factory. Friends with fathers who worked for the confectionery company were seldom without chocolate and sweets, she recalled. But, no doubt, Sir William would be happy to know that his only daughter has a life-long love of cricket.

After briefly working as a teacher in London, she came to Oxford to study music for five years. “I lived on the Iffley Road and I would cycle every day to study with a professor in Wellington Square.” She still fondly recalls playing the organ in The Queen’s College. By then she had already developed close links with the county.

“My aunt and uncle lived in Henley and I would visit regularly as a child. I adored their house and staying with them.” The warm memories encouraged her in the late 1980s to buy Crocker End House, a seven-bedroomed former vicarage, near Henley. The Kents acquired the house, formerly the home of the Earl of Arran, after deciding to leave their home on the Queen’s Sandringham estate.

When she married the duke in 1961 she had become the first woman without a title to marry a royal duke in over a century.

Long before Princess Diana, she established herself in the public mind as a royal willing and able to connect with ordinary people, prepared to abandon protocol to cut through the barriers of awe at openings and official occasions.

Many people continue to associate her with Wimbledon, which she attended with her husband, the president of the All England Club, for 30 years, with her presentation of the trophies as much a part of the English summer as a Lord’s Test.

Bulging cuttings and picture files in The Oxford Times library recording numerous ribbon cuttings and plaque unveilings in Oxfordshire show her to have been one of the most hard-working royals.

Sometimes long associations would result from a visit, as in the case of Helen House, the Oxford children’s hospice which she opened in November 1982 and has continued to support and visit privately.

But after a miscarriage of her fourth child in 1977, she suffered recurrent health problems.

Her withdrawal from the royal circuit later led to claims that she had become a recluse.

Public appearances became even rarer following her decision to convert to Catholicism in 1994, the first senior royal to convert publicly since the passing of the 1701 Act of Settlement.

But we now know the duchess had in fact been busy enough working with UNICEF and then in Hull.

She was encouraged to visit Wansbeck Primary School by a friend who had moved to the city. Overhearing the headteacher speaking about the desperate need for a music teacher, the duchess immediately volunteered her services.

“They have been, without doubt, the most wonderful years of my life,” she now says.

She looks genuinely puzzled when I ask how the children and staff reacted to having a royal among them. “To me that is an odd question. For 30 years of my life I was Katharine Worsley. Who you marry doesn’t change you. I remained the same person. I went on being Katharine Worsley when I was teaching. I was not any different. I only married into it.

“I was shy to start with but I was immediately accepted into the school.”

Early on she recalls asking one group of youngsters about what music meant to them. “Back came the reply ‘nothing’.”

But, undaunted, she first introduced a few rhythm games. Soon the youngsters were being introduced to folk songs and talking about Latin and Italian musical words. “We even did maths to music,” said the duchess.

The demands of the modern curriculum, with the focus on maths, English and science, has too often led to music being sidelined in primary schools, she says in her quiet but firm voice.

“People do not realise that music helps with these three subjects. Music is also the most wonderful way to give self belief. A child gets confidence and is helped to walk tall.”

This confidence, she maintains, is even taken into the exam room.

Her visits to Hull are less frequent now, with much of her energy going into giving children from deprived backgrounds the chance to excel in music through her charity which spots talent, equips children with instruments and in some cases provides tuition to enable them to make music their future.

In 2008, Future Talent Young Achievers was launched and Oxfordshire is to be one of the charity’s four hot-spots (along with East London, Manchester and East Yorkshire), where there will be a special drive to nurture talent youngsters.

Future Talent is already working with Oxfordshire Music Service to ensure the most suitable schools are selected for the programme.

And on May 1, Future Talent will be holding a special young achievers event, which the duchess is hoping to attend. Young people who apply for financial support will be interviewed by a panel and invited to perform at the Centre for Music, based at Bayards Hills School, Oxford. They will be asked to say how much financial help they are seeking and for what purpose.

Listening to her enthusiastically speculating on the young musical talent out there waiting to be unearthed on Oxford’s estates, it strikes me that, in a strange way, she is in the same business as Simon Cowell. But then, of course, unlike Cowell, who has managed to make himself into one of the world’s biggest-earning television celebrities, the duchess’s remarkable mission is to give music as a gift in itself, rather than as a ticket to fame.

And she seeks to do it as far away from the glare of publicity as possible. It is a brave, selfless and, I suspect, sometimes lonely path that she has chosen for herself. But ‘the people’s duchess’ long ago recognised her real hope of fulfilment and happiness meant becoming her own woman.