Gustav Kuhn is an interesting man. A former pupil of Herbert von Karajan, Hans Swarowsky and Bruno Maderna, the 38-year-old Austrian is a conductor who sometimes composes and wants to become a stage director. He also happens to be a doctor of philosophy.

He has enjoyed emphatic operatic successes at La Scala in Milan and at Covent Garden in London. He has led the finest orchestras of Paris, London and Vienna. He has made a number of distinguished recordings.

Obviously, his credentials are in order. But there are problems. Kuhn is said to be difficult. He is idealistic. He is curious. He has integrity, a nose for trouble, and a short temper. He is an impetuous politician and a careless diplomat.

The Lyric Opera of Chicago signed him to a five-year contract. He interrupted that commitment, however, to become Generalmusikdirektor in Bonn.

Bonn, which paid much lip-service to hopes of a cultural renaissance, embraced him with open arms.

For a while.

Bonn is been Beethoven's birthplace and the capital of the Federal Republic of Germany. It is hardly regarded, however, as a world-class musical mecca. The Beethoven Hall often evicts the resident symphony orchestra to accommodate conventions and pop concerts. The local opera house suffers an antiquated stage apparatus, a small pit and a seating capacity of fewer than 900.

Nevertheless, Kuhn approached his new post with apparent optimism. He didn't like the idea of being a jet-propelled guest-maestro all the time. He wanted roots, a place where he could grow, a place where he could experiment, a place where he could build.

The first blow -- a literal trial by fire -- came not from the city government, not from any administrative foes or artistic rivals, but from a perverse fate. Kuhn's duties in Bonn began officially on Aug. 1, 1983. That morning, the Beethovenhalle went up in flames. While it was being rebuilt, concerts had to take place in a tent erected in front of the ruins.

Then came internal troubles with the orchestra. Kuhn intended to improve the caliber of performance and change certain policies. Inadvertently, however, he offended the old guard that wanted to be coddled, and at the same time confounded the new guard that wanted to be challenged.

"I think the day of the conductor-patriarch is over," he observed. "The symbolic turn of the tide can be found in the confrontation between Herbert von Karajan and the Berlin Philharmonic. He refused to conduct again unless the musicians tendered a formal apology for what he regarded as insubordination. But there was no apology, and he has returned anyway. That, more or less, heralded the 'Go tterda mmerung' of the musical dictator."

Kuhn seldom flinched from iconoclasm. It may be characteristic that, in Bonn of all places, he labeled Beethoven a less important composer than either Bach or Mozart. Treading a dangerous line with an essentially conservative public, he instituted a series of "studio concerts" that ignored the beloved Beethoven.

The symphony orchestra, for all its artistic and logistic vicissitudes, represented only half of Kuhn's job in Bonn. The other, more dangerous job, involved the opera. Here he had to contend with a powerful and popular intendant, a Swiss autocrat named Jean-Claude Riber.

The two never enjoyed much agreement as to how the lyric muse should best be served. Complaints could be heard -- or read -- from a general director who may have felt threatened by the ambition and independence of a musical subchieftain 12 years his junior. Conversely, the strong-willed maestro was anything but hesitant when it came to voicing his frustration when he thought his work was undervalued or artistically compromised by his boss.

Relations became openly inflammatory last April when Kuhn said he could no longer bear what he regarded as professional and personal slights. In front of the full cultural committee of the Bonn City Council, he slapped Riber's face.

It wasn't a symbolic slap. It wasn't a verbal slap. It was a smashing, resounding, physical slap.

It wasn't just a slap witnessed by a formal collection of German bureaucrats. It was a slap heard 'round the music world.

The slap was followed by obligatory, perfunctory apologies; still, the furor raged on. The climax followed two weeks later, when Kuhn, still irate, granted an interview to the most influential magazine in West Germany, Der Spiegel.

Even the headline was provocative: "Many Opera Houses Just Produce Vocal Porn."

For openers, Kuhn explained the infamous slap. "It wasn't planned. It was spontaneous. Of course I know that taking a liberty like that in no way solves a problem. That is why I officially apologized. But I must admit I have felt considerably better since administering that slap.

"Herr Riber cannot offer me anything. He buys good singers with a lot of money, proceeds as if this still were 1904, sets them against scenery that belongs in a flea pit, lets them emote -- immobile and without imagination -- as if they were strolling players in a provincial melodrama.

"After these singers have churned out their arias, the public goes crazy, yells and screams, and the Herr Intendant thinks in all seriousness that he has achieved something culturally significant."

He said that the ultimate slap wasn't intended just for Riber, however. It was aimed at a whole system that supports and encourages what the maestro calls "wretched opera."

"There are two kinds of opera," he explained. "One is fair and honest, something for the connoisseur. When it is produced well, it can be likened to a platter of exquisite French cheeses served with a fine red wine. Bonn is still too provincial for that. The other kind of opera is a sort of operatic cheese that just smells bad.

"It involves voice-owners -- I can't really call them singers -- who fake their way through arias . . . Then, when the high notes come, the audience thinks it has experienced opera and starts screaming . . ."

"Actually, the public has witnessed vocal prostitution and has understood nothing about what opera can and should be . . ."

Kuhn didn't just question Riber's sense of artistic responsibility and his modus operandi. Kuhn wondered out loud if the annual Bonn subsidy -- $14 million in all -- was being well spent.

"No one would suggest that a porn movie should be subsidized. Yet many opera houses today are producing vocal pornography, pure and simple."

He also professed little patience with lazy stage directors who do too little. "Take the magic fire in 'Die Walku re.' Usually, the conductor in the pit can muster a decent approximation of magic, and of fire. But the stage is cluttered with big, ugly, brown props. Wotan and Bru nnehilde stand awkwardly among them. A cheap spotlight, one that wouldn't be adequate for a mediocre discotheque, illuminates the catastrophe. Some directors call that a production."

Kuhn's personal solution involves a change in professional life style. "From now on, I want to collaborate only with stage directors whose work I value.

"Essentially, I do not want to make the stage decorate the music. I want to make the stage reflect the music."

The day after the interview appeared in Der Spiegel, Mayor Hans Daniels fired Gustav Kuhn.