Ever since Beethoven, the completion of a ninth symphony has been regarded as a watershed in a composer's development. Hans Werner Henze, who wrote his Ninth Symphony between 1995 and 1997, used the opportunity to write a 55-minute-long choral work, without soloists, in which he came to terms musically and emotionally with a traumatic period of his own early years. He designed the symphony as a summation of his life's work and calls it "an apotheosis of terror and grief" - an outpouring of the experience of living in Germany through the 30s and 40s.

The novel The Seventh Cross by Anna Seghers was his starting point. Henze asked the writer Hans-Ulrich Treichel, who has been his opera librettist for the last 15 years, to provide him with seven poems based upon the seven characters in the novel, who escape from a concentration camp only to be remorselessly hunted down and crucified. Just one of them survives, so that the seventh cross remains unoccupied. Treichel's texts don't replicate the narrative but impressionistically deal with the horror and fear of being a fugitive, of hiding from the hunters and of being captured. It's a dance of death on a massive scale which allows just a glimmer of hope in the final poem as the last fugitive escapes his persecutors.

Every movement in Henze's scheme is dominated by the chorus and their sombre words, yet it is not a quasi-opera nor an oratorio; it is a symphony in its arch-like form and manner. The tumultuous orchestral opening sets the mood in The Escape, as the chorus deliver halting impressions of the fugitive's terror. The second movement is a glacial little slow movement, the third a ferocious scherzo, drastically compressed. The long sixth movement, Night in the Cathedral, is the musical and emotional heart of the work as the escapee hides among the dead; it ends with a string threnody of Mahlerian intensity, and the last movement, with its shreds of optimism, has a provisional, barely affirmative feel.

Ingo Metzmacher, who conducted the premiere in Berlin three years ago, took charge of this searing first British performance. The choir, intense and dramatic when required, was again the Berlin Radio Choir, and the orchestra was the BBC Symphony. Henze's Ninth Symphony is an extraordinary piece, a one-off that is never easy listening, but impregnated with a sincerity and power that are deeply moving.