THE very large Roman Catholic Church of St James, Spanish Place, in the West End of London, was full to capacity for this wonderful concert of Russian Orthodox church music by Tenebrae, a professional choir of 21 singers directed by the former King's Singer Nigel Short.

Travelling in Russia some 20 years ago, Short "became captivated by the intense spirituality of the Russian Orthodox liturgy and the powerful and mystical effect it has when combined with the gloriously sonorous music sung so beautifully by the native choirs". He scoured old music shops for scores, from which grew this concert's programme, by composers largely unknown outside Russia, as well as more familiar names.

We heard an unbroken sequence of 19 pieces, sung by candlelight, all unaccompanied, of course, beginning unexpectedly in the dark at the back of the church with "Priidite, poklonimsia" ("Come, let us worship") from Sergei Rachmaninov's All-Night Vigil, with Adrian Peacock as the sonorous cantor. As this was sung, the singers, with individual lights, moved slowly in procession along the nave to the east end, from which the remainder of the performance was delivered, with only a modest amount of choreography to meet the spatial demands of the individual pieces.

Extracts from the All-Night Vigil and Rachmaninov's Liturgy of St John Chrysostom formed the framework of the evening, which was a concert, not a service; and yet the format, with the audience silent (very silent!) until the end, the darkness, and the processions, cast a spiritual intensity over the proceedings. We were all entranced.

Nearly half of the settings were by Rachmaninov: he was not a believer, but the world of his childhood, swept away by the Russian Revolution, continued to haunt him. It still survived in the Russian Orthodox Church, which for Rachmaninov enshrined many of the values of his family and his youth. Of the Liturgy, Rachmaninov wrote to a friend at the time: 'I started work on it by chance and then suddenly became fascinated by it. Then I finished it very quickly. Not for a long time have I written anything with such pleasure."

In Russia - as in England in the early years of the past century - musicians also sought to minimise foreign influences and look for inspiration in the traditional music of the Church and the people. For Rachmaninov, it was also an exercise in confidence-building after the failure of his First Symphony. Yet for all this he was not completely satisfied with the Liturgy, and to "make amends" he composed the All-Night Vigil five years later.

As Geoffrey Norris has observed, Rachmaninov "relished the resonances of Russian Orthodoxy - its rituals, its chants and the clangour of bells calling the faithful to worship and adorning the great religious festivals". In this respect, he may perhaps be compared for his output of wonderful religious music with our own "cheerful agnostic", Ralph Vaughan Williams.

Beside this great music, no less moving and effective were the other composers' works in the programme, some of whose names, if not their music, are perhaps familiar - Gretchaninov, Kalinnikov, and, of course, Tchaikovsky (his Legend - "The Crown of Roses"); and those whose names may not be known at all - Pavel Chesnokov, Nikolayi Golovanov, and Nikolai Kedrov. Different sounds, perhaps, but with no lessening in quality or spiritual impact.

We also heard several settings of the same pieces, such as "Heruvimskaya pesn" (Cherubic Hymn - by Rakhmaninov, Chesnokov and Golovanov) and "Otche nash" ("Our Father" - by Golovanov and Kedrov). Memorable was Nicholas Madden's soaring tenor solo in "Nine otpushchayeshi" - the Nunc Dimittis - by Kedrov.

I didn't time the applause at the end, but it must have lasted for three or four minutes. The concert marked the launch of Tenebrae's new CD of the same music, Russian Treasures. A smaller group, the Tenebrae Consort, will be performing chant by candlelight and Tallis's Lamentations at St Bartholomew the Great, Smithfield on 13 March. Don't miss it.

Tenebrae's motto is "Passion and Precision", and at St James's there was plenty of both, which succeeded in captivating its hearers and sending us out into the brash West End of London spiritually refreshed and with wonderful sounds ringing in our ears.