Slip into one of the dressing rooms at the Royal Opera House, Covent Garden, and there it remains after all these years. A giant signed photograph of the legendary Australian soprano Dame Joan Hammond as Leonora in Beethoven’s opera Fidelio, during the post-war Covent Garden staging.

Joan HammondDame Joan Hammond in the early 1940s. Photo courtesy of Arts Centre Melbourne, Australian Performing Arts Collection

Hammond saw that Fidelio as “the greatest moment of my career”. Which was saying something. That career encompassed 571 operatic performances, countless recitals, radio broadcasts and TV appearances, plus constant visits to the recording studio. How many classical musicians can boast a gold disc for a million sales of a recording of one short number? Hammond could, thanks to the blockbuster success of her O mio babbino caro (O My Beloved Father) from Puccini’s Gianni Schicchi. More than any other of the wartime recordings made in her adopted home of Britain, this one rendered Hammond the classical equivalent of Dame Vera Lynn.

The late Alan Blyth, distinguished writer on opera, reckoned that long before the Three Tenors, “Hammond carried the banner of opera to...