Jonathan Stewart Vickers (October 29, 1926 – July 10, 2015), known professionally as Jon Vickers, was a world renowned Canadian heldentenor. In 1957 Vickers joined London’s Royal Opera House, Covent Garden company. In 1960 he joined the Metropolitan Opera. . Vickers became world-famous for a wide range of German, French, and Italian roles, but especially in the Wagner tenor roles in Die Walkure, Tristan und Isolde, Parsifal and in Beethoven's Fidelio. He was the foremost Wagner tenor of his era.
https://en.wikipedia.org/wiki/Jon_Vickers