The haystacks have been raked up, the water lilies are clustered; the ballerinas at the Opéra and the revelers at the Moulin de la Galette have taken their places. This year is the 150th birthday of Impressionism, a movement so popular and so familiar that it can seem like some preordained crowd pleaser — all those sunsets and tutus, ready for their blotchy close-ups.

But once, those haystacks were rebellious. Once, those ballet dancers delivered a shock. Can we rediscover what was so revolutionary about impressionism back in 1874? Can we still see the defiance in its beauty, and even its schmaltz?

Right now, at the National Gallery of Art in Washington, two very different paintings hang side by side.

The one on the right, never exhibited in America before, is among the most famous and influential in all of French art. It’s Claude Monet’s “Impression, Sunrise.”