Simone Dinnerstein: Adventures in baby-sitting

Once, she was reciting in prisons. Today, the pianist is a classical superstar. What happened? Bach – and her first child

For concert pianists, the route to stardom traditionally begins in one of three ways: winning a competition, sponsorship by a musical deity, or possession of some handy distinguishing mark – beauty, blindness, or a lurid back-story.

Simone Dinnerstein is beautiful, but had too much integrity to trade on it when she entered the lists: by her late twenties she'd written herself off as a no-hoper for the big league. Her subsequent accidental fame has given the lie to the usual assumptions about what makes a pianistic "star": no flash virtuosity, a very small repertoire, a life devoted to conscientious motherhood in Brooklyn – such things, to the average concert agent, spell box-office disaster. Yet the Bach CD she releases tomorrow is eagerly awaited, and will be a major event, despite the familiarity of its repertoire. What's the secret?

A long, slow burn. Much of Dinnerstein's childhood was spent travelling around Italy with her father, Simon, a leading realist painter, in pursuit of the old masters he wanted to study, which she would dutifully copy, but through ballet classes she fell in love with the piano. Her grandmother gave her a spinet when she was seven, which cemented the instrumental bond. "I wasn't a prodigy," she says, "but I did have a facility." Precise and careful, her manner suggests the decent ordinariness of heroines in Anne Tyler novels. No drama seems to have scarred the surface of her Brooklyn childhood, and her gift was allowed to develop at its own gentle pace. When she listens now to tapes of herself at 11, she is struck by the strength of the musical personality that comes through: "Though lots of things have changed about my playing, I'm basically still the same person, with the same naturally expressive rubato."

She went to study at the elite Juilliard conservatory in New York, but at 18 beat a path to London, partly to be with her English boyfriend (now her husband), but mainly because she was drawn to study, as many now famous pianists have been, with the great Maria Curcio, under whose tutelage she remade herself over three arduous years. Curcio's keyboard philosophy, says Dinnerstein, "was that playing all started from your fingers, pulling the sound out of the piano, as opposed to pushing it into the piano. Pianists in America tend to use a lot of arm, but her emphasis was on the way your fingers touched the keys, even stroked them. She used to quote Rachmaninov's image of pianists as oil prospectors – searching in the keys for a centred sound, which you could pull out. That involved having extremely strong fingers, supported in turn by your wrists, then your arms, then your back. My hands changed shape with her, my span became bigger."

Curcio administered shock therapy, she says, constantly pushing her to attempt things she couldn't do; her next tutor, the virtuoso Peter Serkin, was equally daunting, thanks to his demand that she should memorise a big new piece for every lesson. She became superbly accomplished, but never left the starting blocks in competitions. As she couldn't get an agent, a concert career was impossible. Making the best of things, she enrolled with the Piatigorsky Foundation and began to give recitals in community centres, schools, nursing homes, and prisons.

"I wanted to be happy with what I was doing, because I believed it was valid – I was earning my living as a musician. I took my concerts very seriously, even if they were on terrible pianos in retirement homes."

Then two things happened: she was suddenly offered a debut recital, and found she was expecting her son, Adrian, now nine. "Pregnancy is a strange process, and feels quite long and eventful when you're going through it," she later said. "I wanted a musical project that would mirror this process, and I wanted to master something which I felt both excited and apprehensive about, as I did at the prospect of becoming a mother. And I wanted the baby to grow hearing it." So she started learning Bach's herculean Goldberg Variations, an 80-minute journey through a dramatically changing succession of musical landscapes.

She test-drove the work in schools and nursing homes, and gradually it came together so satisfyingly that she decided to record it using a 1903 Hamburg Steinway, with friends chipping in, as she couldn't finance the recording herself. She sent an excerpt of it to some critics and managers, got sponsorship for a concert in a small Carnegie Hall auditorium, and when a listing in The New York Times mentioned the unreleased recording, they all turned up. The rest is history: following a chorus of critical acclaim, Telarc released the record, which sold a phenomenal 30,000 copies in America in its first year, and Dinnerstein was able to buy the magic Steinway.

As it happens, I was one of the few critics not to like the CD unreservedly, and when I ask her reaction to my strictures on her opening tempi in BBC Music Magazine, she laughs: "That's OK. If everybody loves you, there must be something wrong." But her interpretation is evolving all the time, she adds, and her speeds are now sometimes quite different.

But what's incontrovertible about this recording is the majestic originality of her vision, and the same holds good for her new CD, Bach: A Strange Beauty, which consists of a suite, some chorale arrangements, and two concertos. The title comes from Sir Francis Bacon: "There is no excellent beauty that hath not some strangeness in the proportion." For Simone Dinnerstein, this is a defining quality of Bach's music: "I always think of it as being about symmetry and structure gone slightly awry. He throws in something unexpected all the time. Most of his music is made up of sequences, harmonic progressions, ascending or descending. You expect it to be the same in each measure, but in one of them he will invert the voices, or have a slightly different harmony, and because it's not an exactly repeated sequence it throws off the balance of the phrase, which becomes asymmetrical. Baroque is all about perfect form, and this is un-Baroque." Dinnerstein links this to the paintings she copied as a child: "The art I love – Piero della Francesca, for example – is always a little bit wrong, the dimensions aren't exact, the perspective isn't perfect, there's some distortion. And when it moves away from perfection, it becomes mysteriously human." So it is with Bach: she even likes what Jacques Loussier does with his music.

But she's by no means limited to this composer. The CD she released last year includes an extraordinary account of Beethoven's final Piano Sonata, where visionary beauty alternates with an energetic jazziness, and her chamber music activities now include a double act with the folk singer Tift Merritt. And she's unapologetic about the smallness of her solo repertoire, the by-product of her passionate thoroughness. "Even now, playing the Goldbergs is a lot of work. Before a performance, I need to clear my head of everything else for two weeks. It's like a marathon: you need to build up your mental and physical strength."

Unashamedly home-loving, not happy to be away from her family for long, she's decided to make a virtue of the fact. She has launched a series of concerts in the Brooklyn school where her mother once taught, where she herself was a pupil, and which her son now attends, and she's now expanding the scheme – entitled Neighbourhood Classics – to other schools in the area. These concerts are given at weekends, not as part of the curriculum, and are designed for families and friends as much as pupils, with Dinnerstein interviewing the musicians on stage as both performer and presenter. The musicians play for nothing, the pianos donated by a New York store, so all the funds raised go to schools.

"The idea is essentially local," she says, "connecting musicians and the community, and we get grandparents as well as parents. It's my way of giving something back, a social service. I want to encourage other musicians to adopt schools near where they live, and I'd like the idea to spread further afield. I was inspired by the grassroots aspect of the Obama campaign, of which this is a small reflection." But a very edifying one.

Bach: A Strange Beauty is released tomorrow (Sony)