The Merry Widow.

Prince Danilo falls in love with dancer Sally O'Hara. However, his uncle, King Nikita I of Monteblanco, forbids the marriage due to her being a commoner. Thinking she's been jilted by her prince, Sally marries lecherous old Baron Sadoja, whose wealth has kept the kingdom afloat. When he suddenly dies, Sally must be wooed all over again by Danilo.