Joyce DiDonato greets me with a gigantic smile, although you might expect the rest of her to belie it: the American diva is confined to a wheelchair with her leg in a bright pink plaster cast. Her fall on stage during the first night of Rossini's Il Barbiere di Siviglia at the Royal Opera House in July has shot into the realms of operatic legend. She'd sung to the end of the show despite the pain, then made for hospital, where she learned that she had not only injured her leg, but broken it. One wheel sports a pink paper flower to match the plaster: a signal of how she turned disaster into triumph by integrating the wheelchair into her portrayal of the opera's wilful heroine, Rosina.