Roberta Knie, leading Wagnerian soprano and Philadelphia voice coach has died.

Roberta Knie (13 March 1938 – 16 March 2017) was an American dramatic soprano who had a prominent opera career in the United States and Europe that spanned from the mid-1960s through the early 1980s. Possessing a strong and clear timbre, Knie became particularly known for her interpretations of the works of Richard Wagner.
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 VIDEO: Wagner: Tristan und Isolde - Act I. (excerpt) Lyric Opera of Chicago Franz-Paul Decker, conductor