Jonathan Friend, artistic administrator of the Metropolitan Opera in New York, said Tuesday in an e-mail to opera officials that Behrens felt unwell while traveling to a festival near Tokyo. She went to a Tokyo hospital, where she died of an apparent aneurysm.
Behrens was among the finest actors on the opera stage during a professional career that spanned more than three decades. She made her professional stage debut in Freiburg, Germany, as the Countess in Mozart's "The Marriage of Figaro" in 1971 and made her Metropolitan Opera debut as Giorgetta in Puccini's "Il Tabarro" in 1976.
One of her breakthrough roles came the following year, when she sang the title role in Strauss' "Salome" at the Salzburg Festival in Austria.
She sang 171 performances at the Met, where she appeared until 1999. Her breakthrough there was as Leonore in Beethoven's "Fidelio" under conductor Karl Boehm in 1980, and she was most acclaimed in the late '80s and early '90s for her portrayal of Brunnhilde in the Otto Schenk production of the Ring Cycle.
"She is the finest Brunnhilde of the post-Birgit Nilsson era," Associated Press critic Mike Silverman wrote in 1989. "Though she lacks the overpowering vocal resources of a great Wagnerian soprano, she makes up for that with dramatic intensity."
As a dramatic soprano, she had a Met career that included Elettra in Mozart's "Idomeneo," Isolde in Wagner's "Tristan und Isolde," Senta in "Die Fliegende Hollander," Donna Anna in Mozart's "Don Giovanni," Santuzza in Mascagni's "Cavalleria Rusticana," the title roles in Strauss' "Elektra" and "Salome" and Puccini's "Tosca," and Marie in Berg's "Wozzeck."
Behrens starred in a 1998 L.A. Opera production of "Salome" and performed again with the Los Angeles Philharmonic in 2001.
Behrens was born in 1937 in the north German town of Varel-Oldenburg. Her parents were both doctors and she and her five siblings studied piano and violin as children. She earned a law degree from the University of Freiburg, where she was also a member of the student choir.