The Metropolitan Opera's plans for the coming season include some of the best news that company has sent out in some years.

Among those plans are four stars of the Bolshoi Opera in Moscow who will be joining the New York company, an unprecedented number of Russian singers for any Met season.

The new Russian artists are soprano Makvala Kashrashvili, tenor Vladimir Atlantov, baritone Yuri Mazurok and conductor Yuri Siminov. They will be joined by mezzo Elena Obraztsova who has become one of the Met's biggest stars in recent seasons.

Atlantov's listing among the tenors raises an interesting question. A recent press release stated that Atlantov was changing from tenor to baritone and that he would soon make his debut in the lower range in the role of Renato in Verdi's "Un Ballo in Maschera." The word from the Metropolitan, however, is that Atlantov will sing there as a tenor, the range in which he won himself huge ovations at the Kennedy Center with the Bolshoi Opera two years ago.

His Met debut is scheduled in the role of Don Jose in "Carmen." Kashrashvili, Mazurok and Siminov will make their first appearances in Tchaikovsky's "Eugen Onegin," while Obraztsova will be heard as Carmen, Adalgisa in "Norma" and Charlotte in Massenet's "Werther."

It has been many years since the Met has listed as strong a star tenor section as the one signed for the coming year. In addition to Atlantov, it includes Carlo Bergonzi, Guy Chauvet, Carlo Cossutta, Placido Domingo, Nicolai Gedda, James King, Rene Kollo, Alfredo Kraus, Veriano Luchetti, James McCracken, Luciano Pavarotti, Peter Pears and Jon Vickers.

That's some lineup. It is also interesting to note that the average age of those tenors is around 50, which is about 10 years older than the average leading tenor at the Met 50 years ago. Now there's a trend that cannot continue.

The return of Leontyne Price is a strengthening for the soprano section, though the only role of which she is announced is the title part in "Ariadne auf Naxos" by Strauss, which Price restored to her repertoire last fall in San Francisco, after having sung it 30 years ago at Tanglewood.

Price's colleagues in the upper reaches will include Renata Scotton, Shirley Verrett as Norma, Teresa Stratas, Beverly Sills, Leonie Rysanek, plus Teresa Zylis-Gara, Teresa Kubiak, Katia Ricciarelli, Benita Valente, Judith Blegen, Carol Neblett, and the returning Hildegarde Behrens and Danica Mastilovic.

Among the Met's new productions will be its first "Billy Budd" by Benjamin Britten, in which Peter Pears will sing the role of Captain Vere he premiered in 1951. There will also be new productions of Verdi's "Don Carlo," Smetana's "The Bartered Bride," Donizetti's "Don Pasquale" and Wagner's "Flying Dutchman."

Added to these are revivals of "Ariadne," "The Dialogues of the Carmelites" by Poulenc, which was a great success last year, "Fidelio," "Norma," "Werther," "The Magic Flute," "Elektra," "Aida," Verdi's "Luisa Miller" and "Parsifal." The latter, with Vickers, Christa Ludwig, Bernd Weilkl and Martti Talvela should be memorable.

Another important fact is that the season will begin on Sept. 18 with "Tannheuser" and will run for 30 weeks, three more than his year.

The weekly radio broadcasts, sponsored by Texaco, will be heard again, which keeps the Metropolitan before the country as its principal operatic center. With returning productions of "Butterfly," "Tosca," "Otello," "Rigoletto" and "Traviata," the repertoire and its singer is one of the strongest in many years.

Now if only those crucial participants, the conductors, can touch the proper heights. These will be James Levine, Erich Leinsdorf, Raymond Leppard, Giuseppe Patane, Michel Plasson, Nicola Rescigno, Karl Boehm, Peter Maag, Calvin Simmons, Jesus Lopez-Cobos, Richard Woitach, James Conlon, John Pritchard and Richard Bonynge, a very mixed bag.