The soprano death rate has been fierce at the Washington Opera this season, and all suicides: Juliet Capulet in a tomb next to the body of her beloved Romeo; Madama Butterfly on the blade of her father's ceremonial knife, and poor, harassed Magda Sorel with her head in a gas oven.

It couldn't go on that way, and it has been stopped, at least for now; it's not the kind of problem that is ever permanently solved. But to finish the season, returning from the Eisenhower Theater to the Opera House, Martin Feinstein and company will present two operas in a row that have spectacularly happy endings. Beethoven's "Fidelio" opened last night with Gerard Schwarz conducting and Laila Andersson-Palme in the title role. Massenet's "Cendrillon" will open next Saturday with Mario Bernardi conducting and Frederica von Stade in the title role.

Each opera takes its title from the heroine's assumed name. "Fidelio" is actually a woman named Leonora (like nearly half the heroines of 19th-century opera) who has disguised herself as a man. "Fidelio" can be translated, loosely, as "the faithful one," and the title fits this heroine perfectly. But fidelity is only the beginning of this character.

"Cendrillon" is French for "Cinderella," which is actually a title ("the girl in the ashes," we might say), not a name. Massenet's heroine is really named Lucette. The Prince (a "trouser role" sung by Susanne Mentzer) is repeatedly called "Charming," particularly by Lucette. But that, too, seems to be a nickname.

By any name, the heroines of these end-of-season productions are granted kinder fates than Juliet, Butterfly and Magda, all of whom have now been laid to rest. Rumor has it that the epidemic of soprano suicide will break out anew next fall, when Tosca comes to town. But let's worry about that later.

Since she was plucked from oral tradition by Charles Perrault in 1697, Cinderella has been a perennial best seller in one form or another. But in 1981, she reached the best-seller lists and stayed there for half a year as the subject of a work of nonfiction: "The Cinderella Complex," by Colette Dowling.

Dowling transformed Cinderella into a rhetorical bludgeon to use against women who suffered "fear of independence," who were inclined to "retreat from challenge," who cultivated a helpless air, who avoided ambition, competition and achievement -- above all, women who held back and let men take the initiative and achieve the power and glory.

Nobody has yet written a book about the "Fidelio Complex," but perhaps it's time. Who are the women with the Fidelio Complex, and are they good or bad for society? Beethoven thought they were great; Leonora/Fidelio embodied this crusty old bachelor's feminine ideal. Outside of opera, metaphorically and psychologically, the Fidelio phenomenon dates back at least to the myth of the Amazons.

Not many operatic heroines disguise themselves as men a` la Leonora, though women in trousers have been a commonplace in opera since the time of Mozart -- or since castrati began to be phased out of music. But the trousers are not essential; what matters is the set of attitudes that made Leonora disguise herself and change her name. A quick look at Beethoven's opera may help to clarify what Fidelio represents.

Leonora's husband Florestan is an early sample of that valuable political species, the whistle-blower. "Fidelio's" background is eloquently summed up in a 19th-century libretto whose old-fashioned vocabulary and syntax suit the opera's flavor exactly: "Florestan, a noble Spaniard, a valued friend of Fernando, the Prime Minister, had, by his fearless exposure of the misdeeds of Pizarro, awakened the deadly hatred of the latter. This wretch was not without the means of gratifying his malignity. Being appointed the governor of a fortress, used as a place of confinement for political prisoners, he managed to get possession of the person of his enemy, circulated a report of his death, and immured him in the deepest and darkest of the state dungeons."

As the opera opens, Florestan has been in a dungeon near Seville for two years. He is near death from slow starvation, and Pizarro wants to speed up the process. In his aria "In des Lebens Fruhlingstagen," which might be called "The whistle-blower's lament," Florestan mourns: "I was eager to tell the truth, and these chains are my reward."

But his wife is also his reward. Leonora does not believe the reports of Florestan's death and suspects that Pizarro may have him hidden in that dungeon. So she puts on trousers, calls herself "Fidelio" and gets a job as assistant turnkey. In the process, she embarrassingly wins the affection of Marcellina, the chief jailer's daughter -- but you can't make an omelet without breaking eggs. It takes her months to locate Florestan, whose existence and identity are deep secrets even in the dungeon. Finally, she reaches her husband, just as Pizarro is about to polish him off with a knife.

"Back!" shouts Leonora, leaping between the dastardly assailant and his weak, chained victim in a scene that looks hokey on paper but works well on stage. "Would you stab him?" she cries. "First kill his wife." Pizarro is surprised, but has no basic objection to this suggestion. But when he turns his knife on her, "Leonora quickly draws a small pistol from her bosom and points it at him." "Make a sound," she threatens, "and you are dead."

Taking this gutsy woman as a model, we may posit that the exponents of the Fidelio Complex are not simply women who wear trousers and carry guns but women who want to control their destinies, to be where the action is and to participate in it. They are independent, ambitious, resourceful women who welcome challenges and competition, who are proud of their achievements and do not cultivate subservience to men.

Women of this kind are less rare in opera -- before and after "Fidelio" -- than you might think at first. Joan of Arc (who was given operatic treatment by Verdi and Tchaikovsky) springs immediately to mind as an essentially positive Fidelio type, and there are others.

Rossini tended to favor bright, independent-minded women in his operas. His version of Cinderella, curiously, has some Fidelio qualities. She is a sensible young lady, surrounded by foolish relatives, who goes out of her way to help a beggar at the door, keeps a household running and definitely does not sit around waiting for a prince to come and carry her away.

When Rossini's Prince Charming comes to call, he masquerades as his valet, while the valet masquerades as the prince. And Cinderella, approached by the man she considers a prince, tells him she really prefers to marry his valet. Similar initiative and independent-mindedness are shown by Rosina in "The Barber of Seville" and Isabella in "L'Italiana in Algeri" -- women, significantly smarter than most of the men around them, who take their own destinies in hand and make things happen.

Puccini was, on the whole, more interested in Cinderella types, who almost invariably came to bad ends. But there are exceptions; his Butterfly begins as a Cinderella but develops some strong Fidelio qualities after being abandoned by her pseudo-husband. Similarly, Tosca begins as a Cinderella type (jealousy is one of the symptoms, according to Dowling), but she shifts into Fidelio mode -- tragically, too late -- sometime after singing "Vissi d'arte." In his final opera, "Turandot," Puccini was clearly changing his style, not only musically but in his choice of heroines. The "ice princess," who set deadly traps for any man who dared to love her, shows the dark side of the Fidelio Complex at its most intense. But in the same opera, Puccini includes the intensely Cinderellish Liu, who dies prettily -- a common skill of Puccini's Cinderella types.

For the dark side of the Fidelio Complex, the archetype is Bizet's Carmen. She is a street fighter, a smuggler, a bit of a sorceress and definitely a free spirit, her own woman and nobody else's. She is also (with Fidelio, Joan of Arc and Minnie in "Girl of the Golden West") one of the few heroines in opera who are seen brandishing weapons. In Act 1, she knifes a coworker at the cigarette factory, curiously foreshadowing the final scene, where she is knifed by her rejected lover. At the same time, she remains always intensely feminine, as does that other negative archetype, Nero's ruthlessly ambitious mistress in Monteverdi's "The Coronation of Poppea."

A curious example of the Fidelio Complex gone comically wrong can be found, ironically, in "Cendrillon." Mme. de la Haltie`re, Cinderella's stepmother, is ambitious, resourceful, proud and determined to control her destiny. Her attitude is summed up in the maxim she gives her daughters before they go off to be presented to Prince Charming: "The ballroom is a battlefield."

So, of course, are offices, classrooms and sometimes kitchens, nurseries or bedrooms. Outside of opera, some women have worked out systems that let them be Fidelio from 9 to 5 and Cinderella after dinner. In opera as in life, the polarities of Fidelio and Cinderella are seldom seen in their purest forms, and the variety of mixtures and emphases can be a source of unending interest. So could the fact that men, as well as women, sometimes show the qualities of Cinderella or Fidelio. But the men who compose operas seldom pay much attention to that.