Should we know the story behind the creation of a piece of music, or should we let it speak for itself? The British cellist Steven Isserlis poses this question in the liner note to a CD he has just recorded with the American violinist Joshua Bell. The question is pertinent because the works they play by Schumann and Brahms are seamed with implicit messages by the composers. Moreover, one of those works ends with a ‘codetta’ appended by Benjamin Britten which Isserlis discovered after it had lain forgotten since its premiere fifty-eight years ago: that too has its own poignant back-story. Knowing these things changes the way we listen.

But Isserlis, who has just republished Robert Schumann’s Advice to Young Musicians – including some new advice of his own – is much more than a musicological sleuth: he’s an acclaimed and much sought-after soloist. He also runs festivals, is artistic director of the International Musicians’ Seminar at Prussia Cove in Cornwall, and champions music he regards as underrated; his children’s books about composers reflect a passionate commitment to music education. Few classical musicians can match his influence.

Now fifty-eight, and perennially sporting a wild mop of hair suggestive of a surprised hedgehog, he has a Puckish air: what makes him tick? The key lies in his childhood, and a family tree he is proud to share with Felix Mendelssohn and Karl Marx which stretches back to the sixteenth-century Polish Talmudic scholar Moses Isserles. His grandfather Julius Isserlis – a Russian-Jewish pianist-composer who studied with Tchaikovsky’s pupil Taneyev, and was one of the first Soviet musicians allowed by Lenin to tour abroad (he never went back) – had a direct bearing on Steven Isserlis’s development. He has recorded some of Julius’s charming, late-Romantic music, and Julius’s gold medal from the Moscow conservatoire now hangs on his grandson’s drawing-room wall.

Music-making was central to Isserlis family life. Steven’s mother was a piano teacher, his father played the violin, and his elder sisters were professionals on the viola and violin respectively; taking up the cello, he completed a family ensemble which gave public performances. At fourteen he was taken out of school and spent three years sequestered in Scotland with a teacher who inculcated the basics of his immaculately expressive style; he then studied at the Oberlin conservatory. He has always wanted to emulate the example of the Russian cellist Daniil Shafran, whose instrumental sound was ‘like the voice of a Russian folk singer’.

He was a slow starter: the emptiness of his engagement diary in his twenties made him wonder if he’d ever have a career. But when John Tavener wrote a cello concerto entitled The Protecting Veil for him in 1987, its unexpected success catapulted him to fame. It came at a time when audiences had tired of atonal experimentalism, and Isserlis’s glowingly melodious account of Tavener’s meditation on Greek Orthodox themes chimed happily with the popular mood.

Since then he’s taken an unusually eclectic path, recording the concertos and sonatas of Mendelssohn, Grieg, Fauré, and Walton on the one hand, while premiering works by cutting-edge contemporary composers on the other. The craggy Hungarian miniaturist Gyorgy Kurtag – so terrifying that many musicians don’t dare approach him – composed a solo cello elegy for Isserlis to play after his flautist wife Pauline died early from cancer; Thomas Ades chose Isserlis to premiere the cello concerto Lieux retrouvés, his most lyrical work to date. Yet Isserlis is refreshingly ready to slaughter the avant-garde’s sacred cows, dismissing the late Pierre Boulez – the biggest such beast at present – as having had a deleterious effect on musical life. ‘Now there’s room for everybody, every style,’ he proclaims cheerfully. ‘There’s never been such a great age for new music’.

Isserlis is pre-eminently a chamber musician, whether in period-instrument performance with pianists Robert Levin and Andras Schiff, in Romantic music with Joshua Bell, or in new music (including that of the American composer Lowell Lieberman) with his North London neighbour the pianist Stephen Hough. As a soloist, meanwhile, he acknowledges Bach’s six cello suites as his cornerstone: sublime works which fill him with a mixture of fascination, awe, and fear.

After making his award-laden recording of them for Hyperion, he initially vowed he would never play them again: ‘I love them so much, and they make me so nervous, for fear of letting them down.’ He would never emulate Yo-Yo Ma by performing them at one sitting – ‘the concentration would be too much, for both me and the audience’ – but he recently interspersed them with Kurtag miniatures. If Bach’s suites fascinate him, it’s partly because they exploit the cello’s capacities more satisfyingly than any other music has. And partly because, with his musicologist’s eye, he reads into them a mystical Christian program, from the Nativity to the Crucifixion to the Resurrection.

This article was published in The Economist on October 22 2016