On the strength of her performance in Schumann's Genoveva at the RCM,[2] she made her professional debut as Freia in Wagner's Das Rheingold at Covent Garden in 1911, with the Denhof Opera Company.

She later sang with the Beecham Opera Company in roles such as Nedda, Santuzza, Musetta, Elsa, Desdemona, Sophie, and the Countess in The Marriage of Figaro.

In 1915 she was the soprano soloist in Sir Edward Elgar's incidental music for the first production of Algernon Blackwood's The Starlight Express.

[5] In 1921 they left for the United States with their children, settling in New York, and becoming well known for their joint recitals featuring early English music.

[2] Her notable students included Marge Champion (who was sent to her on Richard Rodgers' recommendation),[8][9] Alfred Drake,[10] Nanette Fabray, Kathleen Ferrier, Celeste Holm, Peter Pears and David Wayne.

She retired in the late 1950s; in 1970 the Royal College of Music established an annual scholarship in her name, The Clytie Hine Mundy Recital Prize, which was discontinued after her death.