Now that Sibelius's marvellous Kullervo symphony can be heard in the concert hall and is available in multiple recordings, it takes an effort to cast one's mind back to the time when it could only be read about in a few books, and none too favourably described at that.

The composer's own negative attitude towards his early masterpiece was no doubt partly to blame for this general critical response. Why, after a great initial success, did he prevent publication and performances of all but the central movement, only allowing this portion of the work an airing late in his life?

The fact that it charts a wide-ranging territory which lies some distance away from the concise structural areas Sibelius was later to make his own cannot blind us to its stunning originality. The composer clearly felt otherwise, but that just goes to show that some creative artists exhibit a mysteriously self-conscious attitude towards their work. It's possible, for instance, that a number of those works that Brahms famously destroyed were actually as fine as the ones he published.

As it is, we can only beg leave to disagree with the mighty composer of Kullervo, and no more convincing proof of his symphony's stature could be adduced than the overwhelming performance it received in Wednesday's Prom under the direction of that dedicated Sibelian, Osmo Vanska.

It seemed at first as if the epic first movement was being a little too lightly treated, with a brisk tempo to prevent heroic indulgence, but as the symphony's huge vistas continued to unfold through the poignant "Kullervo's Youth" and the cataclysmic "Kullervo and his Sister" we felt the narrative screw being inexorably tightened.

The tragedy of Kullervo's unknowing incest and of his sister's consequent suicide allowed us to relish the magnificent sonority of the Helsinki University Male Chorus who delivered Sibelius's runic chanting with majestic intensity, aided by soprano Kirsi Tiihonen and baritone Jukka Rasilainen's haunting solos.

What an incredible movement this is, with its galloping figures, giant paragraphs and shattering conclusion. The BBC Scottish Symphony Orchestra, who had drawn us to the heart of Sibelius's epic world, surpassed themselves here, generating a frightening sense of inevitability within brooding landscapes.

The textural battlefields of "Kullervo Goes to War", all echoing brass calls and unpredictable juxtapositions of sonority, found the orchestra straining at the leash, splendid in all departments, and the tragic finale of "Kullervo's Death" achieved transcendent expression, a true symphonic catharsis.

For me, this will probably remain the Prom of the year, and it also included that other forgotten inspiration of Sibelius's twenties, the extraordinary orchestral ballet The Wood Nymph, the tempestuous allegro in the manner of Lemminkainen's Return, with a crunching change of gear at the mid-point, which vividly proclaims Sibelius's structural mastery.

It was followed by that magical, yet ultimately enigmatic tone-poem Luonnotar, music that masterfully encompasses the mystery of creation. Its runic soprano solo was passionately declaimed by Kirsi Tiihonen. An unforgettable concert.

Anthony Payne