Roberta Knie, leading Wagnerian soprano and Philadelphia voice teacher

Roberta Knie, 79, a leading Wagnerian soprano who sang on the great stages of Europe as well as at the Metropolitan Opera, died from cancer on March 16 at her home in Drexel Hill.

Though her singing career ended prematurely in 1991, Ms. Knie is remembered on videos and recordings, as well as for a 1977 evening of Wagner scenes sung with the Philadelphia Orchestra at the Mann Center during a raging summer storm.

After settling here permanently in 1996, she had been artist in residence since 2004 in the Voice and Opera Department at Temple University and maintained a private studio of students until two weeks before her death. Her students included the tenor Stuart Neill, who has sung in many of the world's great opera houses.

Having been plucked out of a chorus in her native Oklahoma, Ms. Knie enjoyed a prestigious series of teachers including Eleanor Steber. From the mid-1960s on, she sang a variety of roles in European opera houses, including the Vienna State Opera from 1971 to 74.

Ms. Knie sang Wagner's Brunnhilde at Germany's Bayreuth Festival in 1976, in the famous Patrice Chereau production. She also sang at the Metropolitan Opera in 1976 and 1980, and is seen with Jon Vickers on a Video Artists International DVD of Tristan und Isolde excerpts.

She was beloved by her colleagues: When re-united with Vickers a few years later, he exclaimed "I've got my Bobbie back!"

While studying the title role in Strauss' Elektra, Ms. Knie was diagnosed with detaching retinas, caused by the vibration of singing. "I'd rather read than sing," she said in later years. "Think of how much beauty there is to see that I haven't seen. I sing when I'm giving lessons, down an octave. And sometimes I sing up an octave. And it [the voice] is still there."

One of her last stage appearances was the role of Kundry in a Philadelphia Orchestra concert performance in 2005 of Act III of Parsifal, which required only a few moments of her singing.

She is survived by her spouse of 24 years, Deborah Karner. Arrangements are being handled by the Logan Funeral Home. A memorial service will be held 5-8 p.m. April 27 at the Philadelphia Ethical Society.