Giuseppe Filanoti will perform in Jules Massenet's, "Werther," with the Washington Concert Opera at the Lisner Auditorium on May 22. (Nikki Kahn/THE WASHINGTON POST)

In 2007, the Italian tenor Giuseppe Filianoti gave a triumphant New York performance in Francesco Cilea’s opera “L’Arlesiana” at Carnegie Hall. Filianoti, 33, had won fans in his Metropolitan Opera debut; this performance cemented the love. “Remember his name,” said the Associated Press. “He’s going to be a major tenor.”

In 2008, Filianoti was in the headlines again — because La Scala had uninvited him from its opening night at the very last minute. In Milan, Filianoti was supposed to sing the title role of Verdi’s “Don Carlo,” a significantly heavier part for his light, lyric voice. Was the problem a mistake he made during the dress rehearsal; general backstage intrigue; or the fact that he was over-singing, taking on roles that were too big for him?

Officially, all is well again. Filianoti is going back to La Scala in December to open the season in the lighter role of Don Ottavio in Mozart’s “Don Giovanni.” He recently had some good nights — and some shaky ones — at the Met in “Rigoletto.” And Sunday at George Washington University’s Lisner Auditorium, he’s singing the title role in Massenet’s “Werther” with the Washington Concert Opera. But there’s no question he’s in the process of earning back listeners’ interest.

His trajectory mirrors that of all too many tenors. Roberto Alagna, Salvatore Licitra, Marcelo Alvarez, Rolando Villazon: All were hailed as future superstars, none quite met their promise, all are working on combacks of various kinds.

Villazon’s fall was the most spectacular. His ardent performances captured the hearts of a broad public for a few years, but he over-sang so thoroughly that it led to operations on his throat, complete vocal rest and a couple of abortive comeback attempts. He’s now in the middle of a run of “Werthers” at Covent Garden that some are hailing as a true return to form.

Why are so many tenors falling by the wayside? For one thing, everyone is far too quick to overhype young singers, and offer them inappropriate roles. For another, inadequate vocal training leaves some singers uncertain about what they need to do to sustain the pressures of singing day in, day out in big repertory. But the greatest problem of all may be that the business of opera, as it is currently constellated, leaves singers unclear about their goals, aiming not for artistic excellence, but simply for survival.

“In modern life,” says Licitra, 43, speaking from Milan, “it looks impossible to get a career like Placido Domingo, like Luciano Pavarotti, like the glorious tenors of the past. Because this field, it’s [a] mess. The people working in it, they are ill-prepared. I mean from the theater, even the managers, they are concentrated just on organizing some product ready to sell and sell easily by TV.

“When something happens wrong and your voice is not able to perform any more, it’s scary because nobody cares,” he goes on. “Almost everybody is thinking it’s normal to have a short career like that.”

Licitra’s career-making moment came in 2002, when he jumped in as a last-minute replacement for Pavarotti in a “Tosca” that was to have been Pavarotti’s last Met performance. Media and audiences alike were quick to hail the passing of the torch. Licitra had the mien of a handsome teddy bear and a big, ringing voice, and he had been singing major roles at La Scala. He was widely feted as the next tenor sensation — so much so that Sony Classical followed his debut CD with an ill-conceived Three Tenor spinoff called “Duetto,” with him and Alvarez in souped-up pop arrangements.

But the bloom soon faded from the rose. Licitra’s performances can be uneven; different parts of the voice have sounded pushed, sometimes shouty, sometimes strained. (His “Cavalleria Rusticana” in Washington in 2008 was a fine example of a very promising performance that could have been even better with more focus.) His eagerness is tempered by a lack of finesse.

At his former manager’s instigation, he took voice lessons with the Italian soprano Mirella Freni. “Unfortunately,” he says, “it was just wrong advice.”

Still, Licitra continues to have an active career singing at the Met, Chicago and Vienna. From his perspective, his career is going just fine.

“My plan,” he says, “is to try to imitate Domingo and Pavarotti. A long career.”

His comment is telling about how singers conceive of what they do. He invokes Domingo and Pavarotti not for their vocal greatness, but for their longevity. For a singer who has burst onto the scene, enjoyed lots of attention, and seen how quickly it can pass away, the ultimate career challenge is surviving for the long haul in a difficult and potentially hostile climate.

Filianoti feels exactly the same way. “I hope to have a long career like [Alfredo] Kraus,” he says, referring to the Spanish tenor who sang well into his 60s, rather than “a very fast career. . . . Today, we have unfortunately more examples of this. Because the theaters ask you to sing many roles and they don’t care about your age, your possibility, your vocal [abilities]. So you are dazzled by these nice roles that it is important not to do at the beginning” of your career.

What experience teaches, in short, is that flinging yourself into a career with passion and ardor can be dangerous to your health. Villazon has become a kind of example to his colleagues. No one questions his artistry and the depth of his commitment. But just look, the thinking goes, where it got him.

The result, however, may be singers who can make the sounds without truly inflaming the listeners. All of the tenors mentioned above still have careers. Some are singing respectably: Alagna, who was hailed as “a new Pavarotti” before his Met debut and somewhat fizzled afterward, has emerged as an unlikely elder statesman. Alvarez has turned in some decent performances of late. But that seems to be enough.

“What was a thrilling adventure became a business, like being a lawyer,” says Peter G. Davis, the author of the book “The American Opera Singer” and former classical music critic of New York magazine. “You become a singer just like you become any profession in the work force now. . . . That’s why there are so few thrilling personalities . . . burning the stage up, grabbing you by the throat. They’re just not taught to do that any more. They don’t have to.”

There are a lot of intangibles in the singer’s job — including finding a technique that will help two slender folds of skin at the back of your throat hold up to the rigors of repeated heavy singing. This, tenors say, is particularly hard for them.

“The voice of the tenor is the least natural voice in the opera world,” Filianoti said, speaking liltingly by phone from New York. “Because it is a masculine voice that has to have some range that is very high. For this reason it is too delicate, and it is easy to find a tenor with a not-perfect technique.”

Filianoti, however, had a specific reason for vocal hardship. In 2007 — after that triumphant “L’Arlesiana” — he was operated on for thyroid cancer. He kept it as quiet as possible, canceling only a few performances; today, he is cancer-free. But people noticed.

“Immediately, the bad boys in this [opera] world said, ‘Okay, Filianoti had an operation in the vocal cords, he will not come back to sing again,’” the tenor says. “Then, ‘He will come back, but he has not the voice like before.’ This is something that can ruin the mind of [anyone]. But you have to say, ‘This is the world of the opera.’ You have to go on your way, have your focus, your center and go on, straight.”

He cites career advice he once got from the long-lived Kraus. “You have a beautiful voice,” he says Kraus told him. “But remember what is really important: Your mind has to be strong, because you can’t support this career without strength of your mind.”