The distinguished LSO cellist is also an emerging painter who is fascinated by the relationship between art and music. Welsh’s West Hampstead concert tonight doubles as his debut exhibition.

The world of part-time painters better known for other things embraces Winston Churchill, Adolf Hitler and the Kray twins among others. But musicians who take up the brush are relatively rare. Schoenberg and Stephen Hough are two that come to mind, but I’d have been hard pushed to think of any more until I found out about Moray Welsh: distinguished cellist and emerging painter who will be exhibiting himself on both terms at St Cuthberts, Fordwych Rd this weekend.

It’s essentially a concert – Schumann, Beethoven, Debussy and Rachmaninov – with pianist Caroline Palmer. But around the platform will be Welsh’s canvasses, on show for what he tells me is his art world debut – long delayed because, as principal cellist of the London Symphony Orchestra, he never had the time.

He joined the LSO in 1992 and stayed there until 2007. But beyond orchestral dates he always had a parallel life as a soloist and chamber music player, launched when he was a still a student and made a fortuitous encounter with Benjamin Britten.

“I was at York University,” he explains, “when Britten turned up one day, and I found myself playing his Cello Sonata with the composer at the piano. At the end, he suggested we perform it in front of an audience. So there was an impromptu concert. And the pay-off was that Britten arranged for me to go and play for Rostropovich. Which I did, thinking this is either the end or the beginning of everything for me.”

As matters turned out, it was the beginning; and Welsh was invited out to join Rostropovich’s legendary classes at the Moscow Conservatoire, following in the footsteps of Jacqueline du Pre who had just done the same.

It was an interesting time to be in Russia, as the Cold War dragged on from one crisis to the next. But like his fellow students, Welsh became cocooned in the peculiar, heightened atmosphere of the Conservatoire where, he recalls, “being overwhelmed by everything, including the way the teaching was so rigid and took no account of individual personality. There were these amazing instrumentalists all playing in the same way. Which for cellists was Rostropovich’s way.

“His manner was in fact highly idiosyncratic, sitting low and holding the cello high. But the precedents he established were impossible to ignore, especially the control of sound. No cellist had a sound like his, it was amazing and the goal for everybody else. I worked like crazy, trying – and of course not managing – to reproduce it.”

Rostropovich set his pupils other challenges as well, less obviously musical and verging on the dangerous given the state of Anglo-Soviet relations. Travelling back and forth to the UK, Welsh was persuaded to become a courier for items that Rostropovich wanted to send through to Britten, his close friend. And on one occasion it was medicine: “ a supposedly miraculous herb that had been used to cure Solzhenitsyn of various health problems and that Rostropovich thought would be good for Britten who always seemed to be ill.

“It fell to me to bring it over; and of course I was stopped and asked to account for this suspicious-looking substance in my luggage. I had no idea what was in it. So I was arrested while they took it off to a laboratory and pulled it apart. By the time it got to Britten it was probably unusable”.

Welsh’s life these days is quieter, hence the painting. At his house in Brondesbury the walls and stairways are a showcase for his work, which comes in varying styles from realist to radical. “I’m new enough at this business”, he says, “to be still finding out what sort of artist I am.

“But one thing I know is that I’m fascinated by the relationship between art and music. There’s shared territory: practitioners talk of tone and balance, although I’m not sure it means the same in both contexts. And they’re both focused activities: you have to home in. I find that if I want to paint I can’t do it unless I’ve got two or three days clear to see my progress as I go along. Maybe that’s because it engages a different part of my brain to being a musician.”

Whatever the case, Moray Welsh’s double life as player/painter can be seen (and heard) Sat 5th March, 7.30pm, St Cuthberts Fordwych Rd NW2.