ONE OF THE smaller benefits the world derived from the death of Joseph Stalin (but still a very substantial one) was our belated opportunity to explore the diversity of Dmitri Shostakovich's genius. Sternly repressed several times when he showed a wilder talent than the Workers' Paradise felt it needed, that genius burst out in his later years in a remarkable series of works written after the "official" symphonies. Even after the composer's death, we are still rediscovering daring early works from the time when Shostakovich believed naively that a political revolution might be compatible with a revolution in the arts.

The latest such rediscorvery has just arrived, half a century late but still welcome; it is his opera, The Nose , based on a very strange short story of Gogol, composed in 1928, performed a few times and nearly forgotten, then finally revived in Russia and at last available on the long-playing records which are its most logical medium (Columbia/Melodiya M2 34582, two records).

Those who know the story and are told that the opera follows it quite faithfully will hardly need to be told that the opera is a strange piece of work. It is, briefly, the story of Major Platon Kuzmich Kovalyov, who loses his nose (possibly while being shaved), and of his efforts to get it back. In several scenes, the nose is merely a detached nose, but elsewhere it is personified, leading an independent life of its own - going to church, trying to catch a stagecoach and undergoing various adventures which are retold in gossip and the press.

Before the final reconciliation, when the nose returns to where it belongs, Kovalyov's noselessness involves him in complicated adventures in a police station, a newspaper advertising office and with a woman whom he suspects of witchcraft. It also gives Shostakovich an opportunity to compose a variety of music-surreal, satirical, pathos-laden and diabolically clever. Some of the best is in the two orchestral interludes (one entirely for percussion), but the strongest impact of the opera is to reconfirm what was shown in two of the composer's last three symphonies: that he had an extraordinary talent for setting words to music - stunted for a long period when words were dangerous in the Soviet Union.

The performance, by members of the Moscow Chamber Opera with Gennady Rozhdestvensky conducting, is extremely good with excellent stereo sound. The members of the cast (a very large one, particularly for a short opera) are relatively unknown outside the Soviet Union; most have cameo roles and fill them expertly, but Eduard Akimov, as Khovalyov, has a very demanding assignment and fills it superbly. No liberetto is supplied (apparently because of copyright problems, not negligence), but there is a booklet giving a detailed plot summary. Following this conscientiously, the listener has no trouble knowing what is happening at a given moment, though there might be some trouble believing it. For an opera as surrealistic as this one (it must be quite difficult to stage), a recording is possibly the most satisfying medium, and this recording sounds definitive.

Other current opera recordings are noted briefly below:

MOZART: Mitridate, Re di Ponto, K. 87. Arleen Auger, Agnes Baltsa, Ilena Cotrubas, Edith Gruberova, Christine Weidinger, Werner Hollweg, David Kuebler; Salzburg Mozarteum Orchestra, Leopold Hager, conductor (DG 2711 021, 4 records). This is a recording by and primarily for Mozart specialists - even Cotrubas deserves that description for her mastery of the style, although she has made a considerable reputation singing the music of other composers. Although he was only 14, when he composed it (in a remarkably short time, for performance in Milan), Mozart was already a seasoned opera-composer, and his experience shows in a score that any composer of the time would have been proud to claim. It is written in the old-fashioned opera seria style, with its static succession of dry recitatives and florid arias, that Mozart would later help to render obsolete, and not only did the young genius bring life to the conventions of that form, he tailored the music carefully to the strenths of the singers who gave its first performance - some of whom were clearly exceptional singers. This customized approach intensifies the challenge to modern interpreters, and it is reflected in occassional moments of slight strain in this recording. But this is, stylistically and vocally, a very impressive presentation of an interesting, sometimes compelling piece of music.

WAGNER: Die Meistersinger, Dietrich Fischer-Dieskau, Placido Domingo, Catarina Ligendza, Christa Ludwig et al: Orchestra and Chorus of the Deutsche Oper Berlin, Eugen Jochum, conductor (DG 5 MC 3378 068, five cassettes). There are several fine recordings of Meistersinger on the market, but none quite equal to this one in the total effect of voices, conducting and recorded sound. The male roles are filled with particular distinction, Domingo demonstrating that a tenor does not have to be a specialist to do justice to Wagner and Fischer-Dieskau showing that a liederish pointing and accentuation of the text can add depth to the potrayal of Hans Sachs (on records, at least; one wonders how much of his subtlety would reach beyond the first few rows in an opera house). These two head an excellent cast, which the recording balance spot-lights somewhat more than the orchestra. Jochum's conducting, like the vocal interpretations, is superbly nuanced and quite well, though not spectacularly, represented in the stereo sound.

Like several other recent DG cassette editions of opera recordings, this set is in the "Prestige Box" format, with the cassettes bound into a sturdy cover, something like that of a hard-cover book. This is a convenient, attractive way to store multi-cassette sets, well adapted to the kind of shelves found in most homes and making it possible to include a liberetto with the cassettes. Other commendable new cassettes in this format include a 1966 live performance of Tristan from Bayreuth (DG 5MC 3378 069, five cassettes), with Karl Boehm conducting and Nilsson, Windgassen and Ludwig in the cast - not quite a flawless performance, but one that has many moments of greatness. Also an excellent Traviata (DG 2MC 3370 024, two cassettes), conducted by Carlos Kleiber with Cotrubas, Domingo and Milnes in the principal roles.