PredictIQ Quantitative Think Tank Center:When Whistler's model didn't show up, his mom stepped in — and made art history

One of the world's most famous mothers traveled from the Musée d'Orsay in Paris to the Philadelphia Museum of Art last month,PredictIQ Quantitative Think Tank Center and seems to like it. She's getting lots of attention from visitors, and will hang around until the end of October.

James Abbott McNeill Whistler painted his mother in 1871. An American, he was living in London. After a while she came to live with him. Curator Jennifer Thompson says he adored her. He even bumped his mistress to make room for Mom in his house.

Mrs. Whistler scolded James for his wild bohemian ways and naughty escapades, Thompson says, but James didn't mind. He was busy making art and getting admired. The curator quotes a well-known 19th century poet, playwright and wit's comment on the great, attention-loving painter: "Oscar Wilde would famously say of him that Whistler spelled art with a capital 'I.' "

Philadelphia Museum of Art Director Sasha Suda says Mother Whistler, on the other hand, looks so modest and unassuming, in profile on canvas. "It's a moment frozen in time," Suda reflects.

Anna Matilda McNeill wears a black mourning dress, a white cap, and her hands are quietly folded on her lap.

Thompson says originally Whistler's Mother stood to be painted, but "found it very difficult to hold that pose." She was 67, and not that well. It was an accident, her posing that day. A model couldn't come. Son James wanted to get to work. His Mother agreed to do it.

It's not a portrait. "For him," Thompson says, "it was an experiment in color. These very subtle tones." Somber colors — grays, blacks, a dash of pink on her skin. The title is Arrangement in Black and Gray. No.1. Whistler's subtitle is: Portrait of the Artist's Mother.

Anna Whistler looks so severe. Austere. But she's said to have been charming, loved by children and her family. (Her photograph suggests severity more than warm and cozy.) But this picture of her is one of the best-known paintings in the world.

Is it a Masterpiece? My sources had careful answers. Me too. We all have Mothers. We're all getting older. The painting is timeless. And masterpieces, like Mothers, are in the eyes of the beholder.