The Duchess of Kent taught music at Wansbeck Primary School in Hull for 13 years while still serving in the royal family.
It was speculated at the time that she had stepped back from attending frequent royal engagements due to ill health but now details of her other commitment have emerged.
After a visit to the school in 1996, she offered to help boost the school’s arts teaching and her passion project rocketed from there.
Speaking to Hull Daily Mail at the time, the Duchess said: “I’ve studied music all my life, it’s my passion.
“My other passion is children – being able to share and pass on your love of music to children is the greatest privilege a teacher can have.”
The mum, who is now 88, is originally from Yorkshire and has had connections in the region.
The then headteacher of the school, Ann Davies, praised her work.
She told the BBC: “Her enthusiasm with the children brings out the best in them and thanks to Mrs Kent music is now a strength at the school.
“She is an inspirational music teacher and the children love working with her. They say she never gets cross, she always looks for the positive.”
She added: “I believe that because they are so fond of her, they have done well in music.”
The Duchess of Kent’s musical interest started when she was very young. As a schoolgirl, she was taught to play the piano, the violin and the organ, and narrowly missed out on a place at the Royal Academy of Music.
The duchess has three children with her husband, the Duke of Kent – George Windsor, Earl of St Andrews, Lady Helen Taylor and Lord Nicholas Windsor.
However, following the stillbirth of her fourth child, in 1977, she suffered recurrent health problems. After a traumatic 36-hour battle to save her son’s life, which ultimately failed, the duchess was overwhelmed with grief.
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.
However, it was then revealed the duchess had in fact been busy working with UNICEF and then in Hull.
The Duchess now has her own music charity called Future Talent – an organisation aiming to help gifted children develop their musical talents.
The royal also taught children who lived at Grenfell Tower, many of them losing classmates and family members in the devastating blaze that killed 72 people.