Julian Anderson has been the City of Birmingham Symphony Orchestra's composer-in-association since 2001, and with his Symphony, here given its first performances by the orchestra under Sakari Oramo, the partnership is starting to bear significant fruit. The new work - labelled a symphony because, Anderson says, he couldn't think of a more "colourful" title - is cast in a single movement and lasts just 18 minutes, but there are enough ideas to sustain a piece twice as long by many other composers.

Though the music is fundamentally abstract, one of Anderson's starting points was a Finnish painting of melting ice. Everything in his piece seems to be a state of flux, with shapes and tempos constantly changing, and the thematic material always liable to transform itself.

The result is a complex network of musical relationships, laid out with enormous accomplishment in a glistening sound world. But what is harder to reconcile with a musical language that is chromatic and even employs quarter tones are Anderson's sudden attacks of "Englishness" - the passages that evoke ceremonial brass calls or a Delius-like pastoralism. They seem out of place in a work that generally looks beyond these shores for its antecedents.

It is not any easy work, and, as Anderson acknowledges, the final moments reach the limits of playability, but Oramo has prepared this premiere well. He followed it with his own first attempt on Beethoven's Ninth Symphony. If the reading seemed to be feeling its way through the first movement, it began to acquire more of a distinctive character from the Scherzo onwards. In the finale, with the City of Birmingham Symphony Chorus and a fine quartet of soloists led off by the arrestingly operatic bass Clive Bayley, Oramo really went for broke. Even if it's an interpretation that has still to gel, all the ingredients are in the right places.