Yvonne Kenny when she replaced, with only four days' notice, the soprano scheduled to sing in an Opera Rara concert performance of Donizetti's "Rosmonda d'Inghilterra" at the Queen Elizabeth Hall. It was a triumph and the virtually unknown Kenny became an overnight star. She made her debut at the Royal Opera House the following year, in the premiere of Hans Werner Henze's "We Come to the River", later singing in Handel operas such as: "Semele", "Alcina", "Giulio Cesare", and such Mozart operas as: "Idomeneo", "Mitridate, re di Ponto", "La clemenza di Tito", "The Abduction from the Seraglio", "The Magic Flute". She also
Jean Fenn theatre program which was run by renowned Russian tenor Vladimir Rosing. Fenn also studied privately with Amelita Galli-Curci and her husband Homer Samuels in California. She later received vocal coaching from Sigmund Romberg and Erich Korngold. In 1949, while still a student, Fenn sang in her first opera with the Hollywood Reading Club portraying Blondchen in "The Abduction from the Seraglio" and that same year appeared in productions with the Guild Opera Company of Southern California. She made her debut with the San Francisco Opera on October 10, 1952 as Musetta in Giacomo Puccini's "La Bohème" with Bidu Sayão as