A Covent Garden barfly was scanning her programme during the first interval: ‘Oh yes, the one about the gynaecologist.’ She meant Strapless, of course, an attempt to tell the back story to John Singer Sargent’s ‘Portrait of Madame X’, which scandalised the Paris Salon of 1884.

‘Madame X’ was Amélie Gautreau, a Creole beauty who became the trophy wife of a Paris banker (and bat-guano importer).