1921, the beginning of the Golden Twenties. Not far from Paris. It is party day at Marguerite Dumont's castle and like every year, an array of music lovers gathers around. Nobody knows much about this woman except that she is rich and that her whole life is devoted to her passion of music. Marguerite sings, and sings wholeheartedly, but she sings terribly out of tune. In ways quite similar to the Castafiore, Marguerite has been living her passion in her own bubble. The hypocritical audiences that come for a laugh, act as if she is the diva she believes she is, and when a young, provocative journalist decides to write a rave review of her latest performance, Marguerite starts to believe even further in her talent. So despite her husband's reluctance, and with the help of a has-been divo, she decides to train for her first recital in front of a crowd of complete strangers.