Nicolai Gedda, a Swedish singer who rose from an impoverished childhood and a youthful career as a bank clerk to become one of the most celebrated tenors of the 20th century, died of a heart attack on Jan. 8 in his home in Tolochenaz, Switzerland. He was 91.

Widely admired for his sensitive musicianship, masterly tonal control, and impeccable diction in a spate of European languages, Mr. Gedda possessed a lyric tenor voice that shimmered like silver but was no less warm for that.

He was one of the most versatile, and professionally long-lived, tenors of his era, with many dozens of roles to his name in a career that lasted until he was well into his 70s — a good two decades past a classical singer’s customary retirement age.

Mr. Gedda was ubiquitous on recordings and in the world’s foremost opera houses and concert halls, including La Scala in Milan and Covent Garden in London.

Over a quarter-century, he sang 367 performances with the Metropolitan Opera, from his debut in the title role of Gounod’s “Faust’’ in 1957 to his final performance, as Alfredo in Verdi’s “La Traviata,’’ in 1983.

The fluid lightness of Mr. Gedda’s voice made him especially well suited to the French repertoire: His roles included Des Grieux in Massenet’s “Manon,’’ Hoffmann in Offenbach’s “Les Contes d’Hoffmann,’’ Roméo in Gounod’s “Roméo et Juliette’’ and the title role in Berlioz’s “Benvenuto Cellini.’’

Among his Italian roles were Nemorino in Donizetti’s “L’Elisir d’Amore,’’ Ernesto in his “Don Pasquale’’ and Edgardo in his “Lucia di Lammermoor,’’ as well as the Duke of Mantua in “Rigoletto,’’ Alfredo in “La Traviata’’ and Riccardo in “Un Ballo in Maschera,’’ all by Verdi.

But the role for which Mr. Gedda was very likely most famous was Russian: Lensky, the young poet in Tchaikovsky’s “Eugene Onegin.’’

Reviewing Gedda in a concert performance of “Onegin’’ with the Boston Symphony in 1976, Richard Dyer wrote in The Boston Globe:

“The tenor’s voicing of Lensky’s aria — an ideal union of responsiveness to word and musical line, a demonstration of vocal and technical mastery and varied and beautiful tone, and an expression of wise and generous human feeling — was a classic demonstration of why, for some of us at least, operatic singing is the highest achievement of human art.’’

Mr. Gedda’s prowess in a Russian opera is perhaps unsurprising in light of the fact that Russian, along with Swedish, was his native language: He was abandoned as a child by one Russian father and reared by another.

After finishing high school, Mr. Gedda took a job as a bank clerk in Stockholm, earning extra money as a wedding singer.

Through a customer at the bank, he was introduced to the tenor Carl Martin Ohman, who had been a mentor of the renowned Swedish tenor Jussi Bjorling.

Mr. Gedda began lessons with Ohman and later studied at what is now the Royal College of Music in Stockholm.

He made his La Scala debut as Don Ottavio in Mozart’s “Don Giovanni’’ in 1953. The next year he sang Faust at the Paris Opera and the Duke of Mantua at Covent Garden.

Mr. Gedda made his United States debut in 1957, singing Faust with the Pittsburgh Opera. Reviewing his Met debut, in the same role later that year, under the baton of Jean Morel, Howard Taubman wrote in The New York Times:

“His carriage is tall and straight and his movement buoyant. It is credible that he will attract Marguerite. Even more impressive than his appearance is the intelligence of his singing.’’