When French tenor Roberto Alagna replaced the ailing Rolando Villazón in Gounod’s “Roméo et Juliette,” the Associated Press declared Mr. Alagna a “triumph,” proving that a tenor in need is a tenor indeed. This month Mr. Alagna looks likely to reach similar heights in Puccini’s “Madama Butterfly,” which he sings at the Metropolitan Opera beginning October 8. This represents quite a change of destiny for the tenor, whose path has been as rocky as that of any opera hero.

In 1998, under previous general manager Joseph Volpe, the Met dismissed Mr. Alagna and his ex-wife, Romanian soprano Angela Gheorghiu, after Mr. Alagna objected to set designs for Verdi’s “La Traviata.” Last December in Milan, Mr. Alagna walked out during a La Scala performance of Verdi’s “Aida” after part of the audience booed his first aria. Due to such incidents, Mr. Alagna and Ms. Gheorghiu were nicknamed the “Bonnie and Clyde” of the opera world, or even the “Ceaus¸escus” — a particularly unappetizing reference to Romania’s longtime dictator Nicolae Ceaus¸escu, executed in 1989. Just days ago, Ms. Gheorghiu was fired from her role in Puccini’s “La Bohème” at Chicago’s Lyric Opera because she missed rehearsals in order to lend moral support to Mr. Alagna in Manhattan.

Despite this echo of past headaches, Mr. Alagna’s new best-selling compact disc for Deutsche Grammophon, in addition to the reissues of his superb line of opera recordings for EMI and his new French-language memoir,

“Je ne suis pas le fruit du hasard” (I Did Not Happen by Accident), look likely to have changed his tune permanently. At 44, Mr. Alagna has become humanized in the public eye, and is more popular than ever as the best French lyric dramatic tenor in recent history. “Je ne suis pas le fruit du hazard” (Grasset) sold 20,000 copies in France after its first three weeks in print. Recounting Mr. Alagna’s family history, the book goes a long way to explain the origins of his talent. The son of Sicilian immigrants who moved to the unglamorous Paris suburbs of Clichy-sous-Bois in the 1950s, Mr. Alagna sang pop songs for eight years as an entertainer in a Paris pizzeria. (Mr. Alagna has recently returned to these roots with a best-selling CD for Deutsche Grammophon in tribute to Luis Mariano (1914–1970), a joyously effete Basque operetta singer much beloved in France). After serving in the tank corps during military service, Mr. Alagna married, but his first wife died of a brain tumor when she was only 30, leaving him with a young daughter.

This real-life tragedy unfolded in a context of Sicilian family vendettas as recounted in his memoir, which makes turn-of-the-century verismo operas such as “Cavalleria Rusticana” pale by comparison. His great-grandparents fled New York’s Little Italy and returned to Europe in order to escape gang wars in the New World. His great-grandmother was an avid spiritualist, conducting terrifying séances akin to those in Gian Carlo Menotti’s melodramatic “The Medium.”

Small wonder that young Roberto grew up with a lively dramatic imagination. His virile, wholehearted voice at first excelled in lighter tenor roles, such as those in “La Traviata” and Massenet’s “Manon.” Then, under the expert guidance of Antonio Pappano, one of the finest current conductors of the Italian repertory, Mr. Alagna recorded an unforgettable series of opera CDs for EMI, most of them recently reprinted, including Puccini’s “La Bohème,” “La Rondine,” “Tosca,” and “Il Trittico”; Verdi’s “Don Carlos” and “Il Trovatore,” and Massenet’s “Manon” and “Werther.” These are among the most idiomatic, refined recordings of romantic opera ever made, yet some tone-deaf critics have preferred to ignore Mr. Alagna’s musical achievements, and focus on backstage gossip instead.

Mr. Alagna’s way of handling the press may have caused some of the problem. When he was asked by Le Figaro magazine in 2005 about his favorite sport, Mr. Alagna replied, “I do it every night in my bedroom with my wife.” In the same interview, in which Mr. Alagna characterizes himself as “hyperactive, hyperacoustic, hypersensitive, and hyper-foolish,” he admits to a weakness for French screen clowns such as Louis de Funès, Fernandel, and Bourvil, as well as contemporary comedians such as Élie Seimoun and Gad Elmaleh, who draw comedy from their North African Jewish upbringings. In the mausoleum-like atmosphere of the world’s opera houses, this kind of anarchic comic spirit is a rarity.

In interviews, Mr. Alagna sometimes chides his elders, as he did in Le Figaro in 2005, pointing out that he sings “La Bohème” in its original key, while the famed Three Tenors transposed the notes downward for more vocal ease: “People don’t know or don’t realize that Domingo and Carreras never sang it in the original key,” he said, “And Pavarotti stopped doing so at age 40.”

This kind of frankness, and even his walkout at La Scala, have made Mr. Alagna more popular than ever in France where, as the critic Jacques Drillon astutely pointed out in the weekly magazine Le Nouvel Observateur, opera is seen as a stadium sport akin to soccer. Mr. Alagna’s Milan walkout was analyzed as minutely as the 2006 World Cup final against Italy, when the French superstar Zinedine Zidane was sent off for head butting. As Mr. Drillon explains it, Mr. Alagna was booed at La Scala shortly after he appeared, “exactly like a soccer player despised by the crowd.”

Fortunately, crowds of music lovers are showing Mr. Alagna the affection he deserves after more than a decade of superb achievement. His future plans include the voice-destroying title role of Verdi’s “Otello,” and the ideal dramatic role of the French revolutionary poet and eponymous hero of Giordano’s opera “Andrea Chénier” next year in Monte-Carlo. He was supposed to perform the same role at the Met soon, but general manager Peter Gelb preferred to cast Mr. Alagna instead in a new production of “Madama Butterfly,” where despite enchanting melodies, the tenor role of Pinkerton is a dull stick figure. Mr. Alagna has also hinted at reviving a long-neglected opera, Anton Rubinstein’s “Néron,” once sung by Enrico Caruso, which would allow him to incarnate the decadent Emperor Nero onstage. Years of unsympathetic press coverage — now proven to be highly misleading — would imply that this was mere typecasting.