BBC CO / Engegard, Queen Elizabeth Hall, London

Another Nordic Adventure, and after last September's Finnish package, the BBC Concert Orchestra had a better time with Norway. The mix was again classical and folk in the style of Radio 3's Late Junction, complete with Fiona Talkington to present from the platform and a notably obscure repertoire, but the programme gelled and the orchestra played like a snow tiger let out of its cage.

Much of this effect was down to the energy and sympathy generated by Arvid Engegard, a leading violinist developing a career as conductor. Much, also, to a wondrous instrument called the Hardanger fiddle.

This violin variant has extra strings that vibrate freely, like those on a sitar, producing an extra halo of resonance and overtones that colours the sound in haunting shades. In the hands of a virtuoso like Nils Okland, the visiting soloist, it can generate subtle grades and changes of timbre, but the tuning systems and harmonics and drones have limited its appearances in classical music.

Okland dipped into its rich traditional repertoire, including his own compositions, some of the pieces in lively duet with Engegard and some played on conventional violin. More, please, would have been the feeling of many listeners.

The evening moved on to the first-ever piece for Hardanger fiddle and orchestra, a short dance composed 100 years ago by Johan Halvorsen - really an arrangement of an old fiddle tune, with the "orchestra" featuring just the violins.

More of this effect appeared in the Concerto No 2 by Geirr Tveitt, a prolific 20th-century composer whose obscurity is down to most of his scores being lost in a fire. On this showing, he had a flair for combining refined sounds with national feeling - a Norwegian parallel to his Finnish contemporaries Merikanto and Klami.

Because of its length, the concerto had to deal with the Hardanger fiddle's inability to change key. Tveitt tried hard to introduce harmonic variety, but had to fall back on silencing the fiddle and having fun with the orchestra. He found ways to let the fiddle timbre shine through, weaving ingenious chord patterns around it in the darkly coloured slow movement.

But it took a dose of Grieg, in a vivid performance of the Norwegian Dances, to show what real genius could do by way of combining folk-style melody and classical key structures.

The surprise treat of the concert was its premiere, a Radio 3 commission from Anne Dudley, and her final act as the orchestra's composer in association. Northern Lights is a tone poem that follows the form of an aurora borealis display Dudley had seen. Dense string chords shift in regular groups, the rhythm gradually loosening until the pace increases with touches of harp, solo violin, celesta, timpani roll and eventually woodwind. A folk tune sings out, lines intermix. The later stages seemed to need a bigger event than they got, but the end itself, with timpani and string chords, had a quiet, compelling atmosphere that rounded out the sense of subdued wonder.