Proms 2014: Tasmin Little is preparing for her 20th Proms - but busking is her real passion

The chart-topping violinist tells Jessica Duchen that her real passion is for performing for people who never set foot in a concert hall

Off the wall: Tasmin Little busking at Waterloo station (David Sandison)

One summer night in 1990 a young British violinist named Tasmin Little stepped for the first time on to the platform of the Proms at the Royal Albert Hall. That concert – plus her first CD, released around the same time – was the moment that set her stellar career in motion. Now she is back for her 20th Prom, having meanwhile accrued an OBE, a string of classical chart-topping recordings and an enviable global reputation as one of today's best-loved and most sought-after soloists.

At home in her west London flat, Little, 49, reflects that this year's Prom does feel like a milestone. "As it was the Proms that launched me, it has a special significance," she says. "That first one mattered much more than it would have if my career had already been well established. They took a gamble on me – and it worked."

Her 18 intervening appearances there have brought a dizzying range of experiences. "I certainly haven't had many bog-standard ones!" she laughs. She played the fiendishly complex concerto by Ligeti with the Berlin Philharmonic Orchestra and Sir Simon Rattle in 2003, using a newfangled computerised music stand, its scanned pages controlled by a cable-connected pedal. "The software was a bit dodgy and I could easily have been left high and dry if something went wrong," she says. "If only they'd invented the iPad by then…"

In 2012 she shared the stage with one of the world's favourite dogs: the Wallace and Gromit Prom featured her in My Concerto in Ee, Lad. She had to synchronise her playing precisely with the animation on the big screen above her. "I'd expected to be able to do it easily," she remembers, "but that was how I discovered I can't be anything but spontaneous on stage!"

Her spontaneity usually stands her in good stead. In 2007, after the violinist Joshua Bell experimented with busking incognito in the Washington DC underground, I called Little at short notice to see if she could fancy testing the idea in London for The Independent. First there was an astonished pause, then a volley of high-voltage laughter: she was free, so why not give it a whirl? A few hours later she was, most uncharacteristically, playing to passers-by under a railway bridge.

That day, she says, changed her life. Every child wanted to stop and listen to her; and it was young teenage hoodies who were keenest to donate to this mysterious busker what small change they could. Little says she resolved there and then to find ways to bring music to people who would enjoy it if they had the chance, but who were unlikely to set foot in a concert hall.

The result was her project "The Naked Violin": she recorded three works for solo violin and released it free on the internet, "which is like a form of busking," she grins. She went on to play in shopping centres, schools, hospitals, a power station and even on an oil rig, tailoring her performance to audience and setting however startling their challenges and rewards.

"When I went to Belmarsh prison one young guy asked me to play a tune from Vivaldi's The Four Seasons," she relates. "Afterwards he said: 'Thank you, that made my day.'" She maintains a strong stance on the importance of keeping music in the National Curriculum so that it can and must reach every child; and she is much in favour of the BBC's new Ten Pieces initiative, which aims to bring the experience of 10 key works to all the UK's schoolchildren: "Anything that draws their attention to classical music has to be a good thing," she says.

Little's effusive and theatrical personality derives from her family: her father is the actor George Little and her mother came from Stratford-upon-Avon, where she met George while he was working at the Royal Shakespeare Theatre. "I was incredibly influenced by his performing ability," Little says.

On tour he kept in constant contact, sending home recorded voice messages on cassette tapes, international phone calls being impossibly expensive in those days. Little, who is long divorced, says that being in constant contact with her children, now 13 and 11, is likewise her priority when she is away: "My family and my friends are the most important things in my life, even more than my music," she declares. "They ground me; and that's where I find my strength.

"As I have developed as a person, taken some knocks and had to deal with life's challenges, I've become stronger," she acknowledges. "I've asked myself questions about who I am, what I feel and how I'm going to express it – and I hope that has translated into more meaningful performances."

Widespread acclaim for her series of CDs on the Chandos label suggests that it has. The recordings include numerous concertos by British composers – Delius, Elgar, Britten, EJ Moeran, Vaughan Williams's The Lark Ascending – and most recently Walton's Violin Concerto, with the BBC Symphony Orchestra conducted by Edward Gardner. This reached No 1 in the classical charts and spent some 12 weeks in the Top 20. "Of all my recordings, that's the one of which I'm most proud," she says. "I love working with Ed – the strength and intensity he draws from the orchestra is absolutely incredible."

The surprise triumph, though, was the Moeran, a hauntingly beautiful yet rarely heard work by this war-traumatised composer. She will bring it to this summer's Proms in a concert themed around the First World War. "I've had countless messages from people who've heard the CD and wanted to know why it's hardly ever played," she says. "The piece is a revelation – I hope other soloists will take it up too."

One old friend, though, will be missing: Little recently had to return to its owners the "Regent" Stradivarius violin, which she had played on loan for 13 years. "Violins do become partners and giving it up was a wrench," she admits. "It felt like a bereavement." Such beautiful historic instruments are today priced far beyond the pocket of any musician, often sequestered away in bank vaults instead of being heard.

She will perform on the Guadagnini violin that she started to buy via an interest-free loan early in her career… "Unless anyone has a Strad they'd like to lend me?" she appeals, that irrepressible laugh bubbling up again. If you do, please give us a shout.

Tasmin Little plays the Moeran Violin Concerto at the Proms, Royal Albert Hall, London SW7 (0845 401 5040) 25 July