Rimsky-Korsakov's musical revolution in Russia

Born in 1844, Nikolay Rimsky-Korsakov was the youngest member of the St Petersburg-based group of Russian composers that also included Modest Mussorgsky, Alexander Borodin, and Cesar Cui, that formed around Mihaly Balakirev in 1862. Their aim was to create a new authentically Russian music, a style that rejected the heavily Germanic academicism that then prevailed at the St Petersburg Conservatory, and instead looked back to the music of Glinka and beyond him to their own country's folk music roots to establish a tradition.

The hugely influential art and music critic Vladimir Stasov christened the group Moguchaya Kuchka (literally the mighty little heap, and rendered in English as the Mighty Handful), or just as the Five - the shorthand stuck. After that, the history of Russian music in the last third of the 19th century could be handily parcelled up: there was the Five on the one side, and on the other the far more "Europeanised" Tchaikovsky who, though he shared some of the same ideals, was not someone ever inclined to join a group.

Rimsky, who was a serving naval officer when he joined the group, may not have been the most fervent musical nationalist either, and was always sceptical about the possibilities of creating a truly convincing Russian music, but he remained faithful to many of the group's ideals for the rest of his life, and was especially close to Mussorgsky. The two composers shared a studio in the early 1870s, when Mussorgsky was at work on his masterpiece, Boris Godunov, and Rimsky was completing his first opera, The Maid of Pskov; after his friend's death in 1881, Rimsky not only completed the opera Khovanshchina but made performing editions out of the orchestral Night on Bare Mountain and from the ramshackle score of Boris Godunov, reorchestrating it to produce what was the standard version of the work in the opera house until well into the second half of the 20th century.

In his own music, and especially in the 16 operas that form the core of his achievement, Rimsky created a musical world that was permeated by folk dance and song, and frequently coloured by the sonorities of pealing bells, while using subject matter that often made reference to the rituals and pantheism on which so much Russian folk lore and legend is based.

Towards the end of his life, when his pupils included Stravinsky and Prokofiev, Rimsky's position in Russian music was actually much more ambiguous and finely balanced than conventional pigeonholing would suggest. If his pivotal significance to the history of Russian music in general and in Russian opera in particular seems clearer now than it was before, that wider perspective is almost entirely the result of the stagings and subsequent recordings of so many of the operas that Valery Gergiev has conducted in the last two decades at the Mariinsky Theatre in St Petersburg. These have given a far more revealing sense of the scope of Rimsky's achievement than any number of performances of his popular symphonic suite Scheherazade could ever produce in the concert hall.

With that deeper understanding, too, has come a realisation of the importance of his penultimate opera The Legend of the Invisible City of Kitezh and the Maiden Fevroniya, composed between 1903 and 1905, and how it was both a high point of a whole operatic tradition in Russia and its final significant product. By instinct Rimsky was a musical conservative and famously hissed at a performance of Strauss's Salome. But in those years at the beginning of the 20th century he must have increasingly felt himself caught on the cusp of modernism, acutely sensitive to the way in which the musical climate was changing, and that it was a development he was powerless to prevent; after hearing Debussy's Pelléas et Mélisande he begged Diaghilev not to make him listen to "all these horrors, or I shall end up liking them".

As we can see now, musical evolution doesn't conform conveniently to neat historical divisions of style and chronology; boundaries are regularly blurred. What we think of as 20th-century music can be said to have really begun in 1894, with the premiere in Paris of Debussy's Prélude à l'Après-midi d'un Faune, after which the landscape of orchestral writing was irrevocably transformed, and in a similar way the first performance of Rimsky's The Legend of the Invisible City of Kitezh at the Maryinsky Theatre in 1907, brought the curtain down on the nationalist tradition that had been the dominant Russian music for much of the previous century.

Kitezh wasn't Rimsky's last opera, but while he was composing the score he confidently expected that it would be, and so designed it in many ways to be a final musical testament, intended from the start as an epic and the most ambitious of all his stage works, with its roots deep in Russian history and legend.

The librettist for the project was Vladimir Belsky, who had also provided Rimsky with the texts for Sadko (1898) and The Tale of Tsar Saltan (1900). Belsky originally planned that the new work would be based entirely on the life of Saint Fevroniya of Murom, but Rimsky, a devout atheist - Stravinsky later described him rather disapprovingly as having a mind "closed to any religious or metaphysical idea" - rejected such explicitly Christian subject matter and insisted that the story of Fevroniya be combined with elements of Russian history (the 13th-century invasion by the Mongols) and a strong dose of pantheistic legend, with the whole thing given a strongly nationalistic twist. The result is a curious mixture - by turns mystical and realistic, and ending with the utopian vision of the city of Kitezh itself, made invisible by a golden mist, where those killed by the Tartars are sheltered and where Fevroniya and her husband Vsevolod will reign for eternity.

Though there are echoes of Wagner (the score uses the "Dresden Amen" so prevalent in Parsifal) as well as of Mussorgsky's Boris, which combine to give Kitezh its epic sweep, it is the non-naturalistic elements that predictably bring out the best in Rimsky's music, as in Fevroniya's communing with nature in the opening scene before she encounters Vsevolod for the first time. The sheer sweep of the work keeps the drama moving forward seamlessly through each act in a Wagnerian way that blurs the distinctions between different musical numbers; it's not a perfect work - there are a few passages when everything seems to hang fire for too long - but it is a very fine one.

Kitezh did not reach the stage until 1907, the year before its composer's death. By then, though, Russian society was starting to change as radically as its music - the failure of the 1905 revolution had affected the always liberal Rimsky profoundly; he had openly supported the rioting students during the uprising and been briefly stripped of his professorship at the St Petersburg Conservatoire as a result.

His response was to compose another opera, the heavily satirical Golden Cockerel, which, because of problems with the censors, was not performed until after his death. Brittle and facetious, with a score based upon sketches of earlier abandoned projects, the Golden Cockerel influenced Stravinsky significantly, and has become the most widely performed of all Rimsky's stage works; that doesn't mean it's the best or most characteristic of them, though; Kitezh has much stronger claims to be that.

· Valery Gergiev and Mariinsky Theatre perform The Legend of the Invisible City of Kitezh and the Maiden Fevroniya at the Barbican, London EC2 (020-7638 8891), on February 23