FESTVAL: A CELEBRATION OF THE ARTS : A Sight at the Opera : Once, opera was a singer’s art. Now we are in the era of the stage director.

Once upon a time, opera was primarily a singer’s art. The aficionado didn’t care all that much about who happened to be waving the stick, or who was directing traffic. The opera fanatic listened first, and he listened primarily to the sounds emanating from the stage. He looked last, and then without much discernment. Intermission talk revolved around Caruso’s “Pagliacci,” Ponselle’s “Norma,” Melchior’s “Tristan”. . . .

Then, as tastes began to change and vocal standards began to decline, we entered the age of the conductor. It didn’t always matter quite so much who was bellowing the climactic high C or crooning the mezza-voce serenade. Attention had to be paid to the egomaniacal auteur who wielded control in the pit. He wasn’t merely an enlightened accompanist. He was a musical mastermind.

The big shifts probably began with Gustav Mahler at the helm of the Staats- oper in Vienna and with Arturo Toscanini at La Scala in Milan. Eventually, the groupies of the lyric muse had to talk about Karajan’s “Don Giovanni,” Solti’s “Ring,” Bernstein’s “Rosenkavalier,” Giulini’s “Falstaff,” Carlos Kleiber’s “Otello” . . . .

Now, as tastes are changing and the standards of singing and conducting may be declining, we have entered the age of the stage director. Drama, for better or worse, is having its day.

On a bad day, one doesn’t even have to listen. One can read supertitles and abandon the senses to theatrical wizards.

The stage director has become the central, glamorous operatic tyrant. His job is complex. It no longer is enough for him to follow the score and the libretto, to respect the composer’s instructions and to let the music, as it were, do the walking. The current clarion call is to interpret, or, better yet, to re -interpret.

The international in-crowd of the moment talks about Zeffirelli’s “Turandot,” Kupfer’s “Fliegende Hollaender,” Sellar’s “Cosi fan Tutte,” Wieland Wagner’s or Chereau’s or Rochaix’s or Friedrich’s “Ring”. . . .

And so it may go at the Los Angeles Festival. The operatic schedule heralds Puccini’s “La Boheme” as staged by Jean-Pierre Ponnelle, Prokofiev’s “Fiery Angel” as staged by Andrei Serban, and Rossini’s “Cenerentola” as staged by Frank Corsaro.

The Ponnelle “Boheme,” familiar from its San Francisco incarnation in 1978, takes no drastic liberties with the original. It does, however, banish some tired character-cliches and, as it vividly evokes an impoverished verismo Paris of 1830, it scrapes away many a meaningless barnacle of tradition.

One doesn’t know what to expect of “The Fiery Angel,” but with Serban in charge it won’t be dull. He, you may recall, is the Romanian avant-gardist who once shocked Juilliard with a blood-guts-and-nudity “Traviata.” He also is the relatively noncontroversial director who staged the exotic, stylized, anti- kitsch “Turandot” that introduced the Royal Opera of London to our Olympic Arts Festival.

In the distant 1960s, Corsaro’s productions at the New York City Opera seemed to mark him as a violent enfant terrible . Today, the same productions seem only mildly gimmicky, and subsequent efforts by the same man of the theater haven’t even been provocative. One trusts he will exercise comic restraint when he turns his fertile imagination loose on the Cinderella story as filtered through romantic Italian sensibilities.

Many observers regard the rise of the operatic stage director as a trend that is at least potentially healthy. Of course there are aberrations, exaggerations, distortions, excesses and indulgences to be regretted. Some theatrical autocrats have instigated change for its own sour sake. There are nights at the opera when the cognoscenti have trouble recognizing the source. There also are nights, however, when opera actually makes sense as musical theater.

What seemed perfectly acceptable in 1940 may look perfectly preposterous in the cool light of 1987. We have come a long and painful way from the silly caricature of the concert in costume. At least we would like to think we have.

It must be acknowledged that temporal observations in the history of opera production invite dangerous generalizations and oversimplifications. Trends are never crystal clear. Periods overlap. A chic chapeau in one country is an old hat in another.

For many practical purposes, however, it can be argued that the revolution in operatic drama began in Germany, right after World War II. Germany has always tended to be more adventurous than other operatic countries. Thanks to generous state and government subsidies and a strong public-education program in the arts, the country always could afford intellectual experiments in the opera house.

In the late 1940s, however, there was little money for the arts. Many theaters had been destroyed. Some that survived had no sets or costumes.

In Bayreuth, Richard Wagner’s grandson Wieland turned physical necessity into artistic advantage. He knew that bear-skinned Heldentenors and breast-plated sopranos emoting wildly in front of tattered, literal scenery could no longer be taken seriously. He also knew that funds for elaborate alternatives were not at hand.

Therefore, he created what amounted to a new style. He stressed understatement, symbols and abstractions, used lights to convey moods, and designed a new sort of barren, open set. He made his actors stand still and reduced their gestures to stark essentials.

At first, the traditionalists felt betrayed. By the time of his untimely death in 1967, Wieland was revered as an operatic saint, or at least an unreasonable facsimile thereof.

He also was much imitated. Less inspired and less inventive directors tried to preach variations on the same daring gospel everywhere. Unfortunately, their compromises weren’t daring and their sermons weren’t convincing.

Before long, alternative schools emerged. Goetz Friedrich, a disciple of the legendary Walter Felsenstein, explored the possibilities of heightened realism and social commentary. Patrice Chereau and Harry Kupfer introduced special political and psychological insights, blithely playing loose, if necessary, with customary definitions of time and space.

Meanwhile, in Italy, Luchino Visconti, Franco Zeffirelli and, after his own masterly fashion, Giorgio Strehler went their own picturesque way. They placed great stress on stylish sets and on cinematic credibility. They tried to banish cliches and played instead for elegance.

In recent seasons, Zeffirelli’s increasingly lavish, increasingly vulgar concoctions have all but smothered the singers and snuffed out the music. His “Turandot” at the Metropolitan Opera looked like a shamelessly gaudy, Gargantuan birthday cake with a tiny musico-theatrical pageant mired somewhere in the frosting. His overwrought “Otello” film managed to offend anyone who respects either Verdi or Shakespeare. But, his work wasn’t always like that.

The mass audience in America, especially in New York, has not been terribly receptive to operatic innovation. Fun City still applauds the scenery. The music be damned, or at least obliterated. The Met public is especially pleased if a house on the stage really looks like a house. The same crowd applauds any frightened horse or dog that may add color to a crowd scene. New York still likes opera to look fancy and old-fashioned.

Perceptions and attitudes can be different, however, out of town. The operatic mirage in Santa Fe has long welcomed experimental concepts. San Francisco encouraged the reasonably progressive ideas and ideals of Jean-Pierre Ponnelle before he became a household name even in Munich. Two summers ago, Seattle abandoned its quaint-antique “Ring” in favor of a bizarre, often contradictory flight of post-mod quasi-Brechtian fancy, staged by Francois Rochaix and designed by Robert Israel.

While Los Angeles foundered in decades of operatic misfortune--or, worse, in no operatic fortune at all--the dauntless little Long Beach Opera ventured futuristic variations on familiar works as envisioned by Christopher Alden and his twin brother, David. The first season of Music Center Opera proved more conservative, but it still reflected serious theatrical attitudes. The new era began with Goetz Friedrich’s somewhat inconsistent “Otello,” a disappointing prelude to Sir Peter Hall’s decadent- Jugendstil “Salome” and Corsaro’s brashly stylized “Alcina.”

The most effective modern stagings, of course, are those that reveal a vital dramatic perspective without going against the musical grain. A good director must be a sensitive musician. He must understand the expressive dynamics of the work at hand, not just the basic plot outlines. He must not ignore the score when searching for a novel subtext.

West Berlin has an “Orfeo ed Euridice” production in which the noble mythological hero is a sad, white-faced clown who wears oversize tennis shoes. One German city used to have a comic-book “Don Giovanni” in which the protagonist actually impersonated Superman. The same house also got a lot of mileage out of a revved-up “Walkuere” in which the lusty warrior maidens became leather-clad lesbians on motorcycles.

Such conceits may be amusing, in their sweetly outrageous ways. But they force one to ask whether they shed new light on the works in question or merely obfuscate. Gluck, after all, did not write buffoon music for his Orfeo. Mozart’s delineation of Don Giovanni is much too subtle, much too aristocratic to accommodate a cartoon. Wagner’s heroic ride conjures up visions of lofty wings, not grimy wheels.

One must be careful. The line separating the boredom of old rituals and the excitement of new discoveries is a treacherous one. Ideally, opera should unite strong singers and a strong conductor and a strong director, all devoted to a common vision.

Genuine collaborations between great artists are as rare as snowballs in Arabia. But when they happen, the world remembers. Milan is still talking about the “Traviata” of our time--the one that took place at La Scala more than three decades ago, in May, 1955.

Significantly, the legendary event wasn’t Callas’ “Traviata” or Giulini’s “Traviata” or even Visconti’s “Traviata.” It was Verdi’s “Traviata.”

Some day, perhaps, we will revert to the age of the composer.