For John Singer Sargent enthusiasts, Gilded Age buffs, and fashion historians alike, the story of Madame X’s notorious debut at the Paris Salon of 1884 is a tale as old as time. When the prodigious 28-year-old painter immortalized the idiosyncratic beauty of Madame Pierre Gautreau, a fellow American in Paris, he rendered her precisely—from her auburn chignon and prominent nose to her lavender-tinged complexion and figure-hugging black dress, whose jeweled strap had slid off her right shoulder.

Yet scandal quickly followed, the latter detail doing little to dispel Madame Gautreau’s already controversial reputation. Savaged by critics for the portrait, Sargent famously repainted the strap in the upright position—but the damage was done.

In 1915, after holding onto the painting for more than 30 years, Sargent—who eventually resettled in London—sold Madame X to New York’s Metropolitan Museum of Art, where it has become a highlight of the collection. “It’s a portrait that’s so compelling, and people are always so fascinated and want to know more about her,” Stephanie L. Herdrich, Alice Pratt Brown Curator of American Painting and Drawing at the Met, tells Vogue. Over the last three decades, Herdrich has become a specialist in all things Sargent, proudly calling herself Madame X’s “caretaker, travel companion, and PR rep.”

“Even though people think they’re familiar with the painting’s story,” she adds, “I thought there was more to say about it.”

John Singer Sargent, Madame X (Madame Pierre Gautreau), 1883–84. Oil on canvas. 82 1/8 x 43 1/4in. (208.6 x 109.9cm). Arthur Hoppock Hearn Fund, 1916 16.53 The Metropolitan Museum of Art