This fiddler comes with an organic farming certificate

The most pleasing aspect of Vilde Frang on first sight is her resistance to typecasting. On the eve of an international record launch, with hedge funds rising and falling on her success or failure, the Norwegian violinist has held out against makeover pressure.

She appears with rare wholesomeness in harvest-ready wheaten hair that falls below her shoulders and an unshadowed hint of plumpness in her cheeks. Before she plays a note, we know there is nothing affected about this artist.

Upstairs at London's Foyles bookshop, for a browser audience unprepared for rigour at the end of a winter's working day, she delivers Bartók's sonata for solo violin with prodigious intensity, missing some of its world-weary humour but compensating with a brisk empathy for its rural song fragments. Written for Yehudi Menuhin by the cancer-stricken composer in American exile, the sonata is tough on fingers and intellect, half an hour long. The attention was unbroken by a single cough.

In a classical recital hall, Frang would have been applauded for courage and accomplishment, and punctuated by tubercular outbursts between movements. In a bookstore, she achieved communication with people unprepared for what she played.

These are promising signs for a young woman of 23, at the start of her career. Comparisons and antecedents can be eliminated. Although mentored by Anne-Sophie Mutter from the age of 10 with financial support and the loan of a French instrument, Frang has nothing like the Mercedes-smooth sound of her patron, nor does she present herself for any kind of catwalk. She looks more like a folk singer than a classical star, and that's no bad thing.

What we see is what we hear - an organic artist, unmoulded by the music industry, ready to go wherever her gift may lead, and lacking in all pretension. Her debut recording of Prokofiev and Sibelius violin concertos is out this month.