rewrite this title Edith Mathis, Radiant Swiss Soprano, Is Dead at 86

“When I try a role, if I feel it’s too heavy for me then I will never do it,” she told Mr. Duffie. “I might just wait perhaps until later, but I wouldn’t do something which hurts the voice, and where I have to force against the orchestra. That’s impossible.”

Edith Mathis was born in Lucerne, Switzerland, on Feb. 11, 1938. She once recalled in an interview with the Neue Zurcher Zeitung, Switzerland’s leading newspaper, that her parents, and particularly her mother, cultivated her ambition to sing. In her teenage years, she said, she typed invoices in an office in the morning, to placate parents worried about the uncertainties of a career in music, and in the afternoons went to the local conservatory. She also studied at the conservatory in Zurich.

She made her operatic debut in 1957 at the City Theater in Lucerne as the Second Boy in “The Magic Flute.” From 1959 to 1963 she was part of the ensemble at the Cologne Opera House, and in 1963 she joined the Deutsche Oper in Berlin.

She first sang at the Salzburg Festival in 1960, in a concert, and at the Glyndebourne Festival in England, as Cherubino, in 1962.

She won a number of awards for her recordings, including the Prix Mondial du Disque de Montreux, in Switzerland, and taught song and oratorio at the University of Music and Performing Arts in Vienna from 1992 to 2006. She made her last appearance as a singer in 2001.

Ms. Mathis is survived by her husband, Heinz Slunecko, an art collector, and two children, Bettina Mathis and Tom Mathis. An earlier marriage, to the conductor Bernhard Klee, ended in divorce.

In her interview with Mr. Duffie, Ms. Mathis spoke of the singer’s isolation:

“We have no excuse,” she said. “A conductor can say, ‘They didn’t play well for me,’ and a pianist can say, ‘The piano was very bad, and was not in tune, or was a very old instrument,’ but we singers are our instruments, and we have to do the whole business ourselves.”