On any list of the greatest music composed in this century, at least two works related to World War II must find places near the top: Benjamin Britten's "War Requiem" and Olivier Messiaen's "Quartet for the End of Time."

Both, curiously, have a strong though hardly conventional religious flavor. More important, perhaps -- and more typical of the 20th century -- both convey the special beauty that rises out of the deepest pain.

Britten's masterpiece had its first performance on May 30, 1962, and passes its 25th anniversary this weekend. It was commissioned for the dedication of the new Coventry Cathedral, which replaced the building systematically destroyed by Nazi bombing during the war.

This week, Mstislav Rostropovich and the National Symphony Orchestra will mark that anniversary, with one singer who participated in that original performance, soprano Galina Vishnevskaya, singing again the music that Britten wrote for her. An irony unforeseen by Britten will give added depth to the performance. Vishnevskaya and her husband, Rostropovich, are now exiles from their native country, victims of the war that is the subject of the music -- a war that has not really ended but simply slipped into other modalities.

The press gave no attention to the premiere of Messiaen's quartet, which was first performed in a German prison camp during the war. But Britten's Requiem was recognized from the beginning as one of the thematic works of the century. Seldom has a piece of occasional music been found so completely appropriate to the occasion.

By its very structure, the "War Requiem" demands recognition as a major statement. It is a massive work, using enormous performing forces and one of the most frequently set liturgical texts in the history of music. By the circumstances and by the structures he set up, Britten challenged himself. Nothing less than a masterpiece would do for this occasion and these performers -- and, of course, he produced the required masterpiece.

What striking, new things can a modern composer do with the text of the Requiem Mass after the treatments by such composers as Mozart, Berlioz, Verdi and Faure'? Britten took the two essential themes of the Requiem Mass, terror and consolation in the contemplation of death, and focused them specifically on the subject of modern war. To clarify and intensify his message, he used poems by one of the most eloquent antiwar poets of the century, Wilfred Owen, who died in combat a week before the end of World War I.

These poems, sung in English, are distributed through the Latin text like the chorales that periodically interrupt and comment on the narrative in the passions of J.S. Bach. But these texts are not assigned to the chorus; they are given to the tenor and baritone soloists (accompanied by a chamber orchestra) who represent English and German soldiers suffering and expressing the horrors of war. The Latin text is entrusted to others. A boys' chorus seems to represent angels and saints dedicated exclusively to the contemplation and praise of God. The soprano soloist, large chorus and large orchestra embody humanity, offering the Requiem and confronting the emotions related to death -- the pity, terror, consolation and reconciliation that are evoked in the ancient Latin text.

Britten's music matches all of these dramatic and emotional implications. The God implied in the "Dies Irae," making the earth tremble with his destructive wrath, contrasts sharply with the God of static splendor (almost like a Byzantine icon) evoked in the "Sanctus," where the soprano sings accompanied by bells. The unworldly, contemplative beauty of the boys' chorus in "Te decet hymnus" is a universe apart from Owen's bitter, ironic poem on Abraham and Isaac that accuses the world's rulers, in effect, of worshiping their own pride and sacrificing their own sons in that worship.

This is assigned to the tenor and baritone, who also have the false bravado of "Out there, we've walked quite friendly up to Death," the pathos of "Move him into the sun" and many other emotions, ending with the gentleness of their final duet and its repeated, quiet invocation: "Let us sleep now. . ."

A special sense of the occasion went into the choice of the three soloists for the "War Requiem's" first performance: Vishnevskaya, tenor Peter Pears and baritone Dietrich Fischer-Dieskau. They were chosen as natives and representatives of three of the war's hostile powers -- Russia, England and Germany. But they were also three of the world's leading singers of that time. Each voice had a unique quality, instantly recognizable by the most casual listener; each was matched by no other voice in its specialized repertoire, and all were then at the pinnacle of great careers.

A replaying of the recording conducted by Britten in January 1963 confirms that the "War Requiem" has lost none of its power in the quarter-century since it first burst upon the world. Even the 1963 sound, which might be expected to seem a bit pale compared to the high-tech recording achievements of the '70s and '80s, remains dazzling. It was, after all, in the hands of John Culshaw and his technical wizards from London/Decca, a company that had been showing the world the possibilities of high fidelity since the era of 78 rpm recordings.

Transferred to compact discs some time ago (London 414 383-2, two CDs with booklet), Britten's recording sounds better in this new medium than it has ever sounded on LP, cassette or 7 1/2 i.p.s. tape. Mastered with loving care, the CD edition puts listeners in direct contact with the original master tape -- an extraordinarily vivid and versatile piece of engineering.

The recording functions effectively on many levels and in a variety of sound-textures ranging from chamber music and solo voices to massive orchestra and chorus with brass and drums proclaiming the end of the world in the "Dies Irae."

Participants in Britten's recording included the vocal soloists, the Bach Choir, the London Symphony Orchestra Chorus, the Highgate School Choir, organist Simon Preston (playing a chamber organ), the Melos Ensemble and the London Symphony Orchestra. Each of these performing elements ideally requires a somewhat different sonic perspective for the best effect. As conductor, Britten had the major responsibility for coordinating and balancing these forces, but his efforts were artfully reinforced by Culshaw and his crew. The recording perspective shifts frequently from the panoramic to the close-up, but there is never a sense of discontinuity or manipulation.

The performance is magnificent. Britten was a first-class interpreter (of others' music as well as his own) and he found collaborators of equal quality, all of whom were clearly aware that they were performing great music and making history. More than Bach, Mozart, Beethoven or any composer before the invention of recording, he was able to leave precise examples of how he wanted his music performed.

That example has been followed with exemplary precision and the highest musical and technical standards in another recording of the "War Requiem," conducted by Simon Rattle (EMI CDS 7 47034 8, two CDs with booklet). Rattle's marginal advantage in 1980s recording technology does not outweigh the presence of the composer and his chosen soloists on the older recording, but his performance is still a remarkable one, particularly for its fidelity to Britten's ideas as preserved in Britten's recording. It is also testimony that the "War Requiem" is indeed a classic -- which means, among other things, that it is able to be reborn powerfully again and again in new performances.

Those who are fascinated by Britten's settings of Wilfred Owen may be interested in an earlier one that has just been reissued. In his Nocturne, a vivid song cycle for tenor, strings and seven obbligato instruments, Britten includes a superbly atmospheric setting of Owen's "She sleeps on soft, last breaths" with a wonderful solo for English horn.

Britten's recording, with Peter Pears, was withdrawn from circulation some time ago but is now reissued on a newly remastered CD (London 417 153-2) together with the Serenade for tenor, horn and strings and "Les Illuminations."

The latter two works originally filled a single LP, and the addition of the Nocturne in the CD remastering helps to compensate for the somewhat higher CD price. It adds nearly half an hour to the playing time (bringing the CD up to 73 minutes), it puts together on a single disc Britten's three major song cycles for solo voice and orchestra, and it preserves the three most important nonoperatic recorded collaborations of these two artists. Anyone who is interested in Britten's vocal compositions will want to hear and probably to own this disc.