Reginald Marsh. Zeke Youngblood’s Dance Marathon, 1932. © 2013 Estate of Reginald Marsh/Art Students League/Artists Rights Society (ARS), New York. (Reginald Marsh/© Munson-Williams-Proctor Arts Institute / Art Resource)

Decades before John Updike wrote of flat-stomach nymphs parading in bikinis, and well before Slim Aarons focused his camera on the tanned and toned at St. Tropez, Reginald Marsh was sketching at the beach.

He was drawn, like any painter, by the unclothed bodies, but he wasn’t after the cool surface beauty of conventional summer icons. Painting in the 1930s, Marsh was attracted to energy.

By all accounts a shy and awkward man, he was fascinated by extroverts and physical control. He had a voyeur’s eye for dynamics, turmoil and collapse. And so he depicted the rough, restless upheaval among working folks seeking a brief window of relief on the sand: the pushy exhibitionism on Coney Island and the aggressively uneasy sprawl on Rockaway Beach.

The shore isn’t always an escape, as any August beachgoer knows. The crowds, the flies, the self-consciousness; the often uncomfortable loosening of decorum as well as dress codes. That jammed-up sense of conflict leaps out at you in “Swing Time: Reginald Marsh and Thirties New York,” on view through Sept. 1 at the New-York Historical Society.

Well, I’ll take a chance on anything titled “Swing Time.” This show, the first major retrospective of the American scene painter’s work in more than 20 years, doesn’t disappoint as a journey back to a perennially absorbing era. First things first. There are T-strap pumps and Marcel waves to die for; men in hats; bias-cut dresses, skirted swimsuits. Fur stoles? Only in the store windows, out of reach of the passersby. This isn’t a Fred-and-Ginger world.

Reginald Marsh (1898-1954), Star Burlesque, 1933. Curtis Galleries, Minneapolis. © 2013 Estate of Reginald Marsh/Art Students League/Artists Rights Society (ARS), New York. (Reginald Marsh)

But many of Marsh’s subjects are the kind of independent characters Ginger Rogers played in the dozens of movies she didn’t make with Fred Astaire. In “BMT 14th Street” (1932), working people cascade down stairs into the subway system, a descent into hell that Alfred Hitchcock, with his own staircase obsessions, would understand. The focus is on women, dressed for the office, or for shifts at Macy’s, perhaps.

It’s a self-conscious statement of the changing times. A well-dressed woman in the foreground carries a purse in one hand, a stack of books in the other. Caught in mid-stride, she looks at you with a sidelong gaze, eyes narrowed, as if you’re some oddity in the corner. (Imagine Marsh bent over his easel, a strange fixed point in this rushing stream of humanity.) On a staircase in the background, a large woman pushes uphill through the throng of men with the weighty might of a Russian babushka.

There are two Marsh murals in Washington’s William Jefferson Clinton Federal Building, the former Post Office Department headquarters : “Sorting the Mail” and “Unloading the Mail” (1936), which show the fast pace of these labors organized in harmonious swirls of activity.

Yet, in the “Swing Time” exhibit, it’s clear that Marsh excelled at the art of confrontation. He seized the peculiar tension of the ’30s, when the urban population was being pushed around, physically, by fast-changing forces beyond its control. These were a combination of dire economics, the inescapable allure of Hollywood (there are marvelous paintings of sidewalk scenes outside movie theaters), the ceaseless crowds and the limited avenues of escape — beaches, burlesque shows, carnivals.

Marsh was a New Yorker magazine cartoonist and serious student of the old masters before he became a painter, and this exhibit is infused with the sketchy vigor and fleshly voluptuousness of those two endeavors.

The curators clearly think “Star Burlesque” (1933) is the highlight, and it is given pride of place on a central wall. It is indeed magnificent, depicting a statuesque stripper in fluffy Jean Harlow hair and makeup, eerily aglow in a greenish artificial light. Naked but for her thong and winglike ruffles around her upper arms, she is an alabaster Venus with kewpie-doll lips. Or is she Zeus? One arm is raised over her head, just waiting for a lightning bolt to hurl.

Behind her, under her armpit, actually, we see three men seated in the flag-draped VIP balcony of an ornate theater. They study the stripper somberly, joylessly. (One even looks angry.) The painting drips with decadence and dualities. The men are framed on their curtained balcony as if they’re on a stage of their own. Or in a trap, and we’re catching them in their shame. Meanwhile, the dancer is far grander than them. She is powerful, unattainable, mythical in her zombie light.

Then again, she’s utterly exposed, vulnerable. Her face is expressionless. She doesn’t seem to be having any more fun than her male fans.

Paintings such as this are why Marsh continues to mystify art lovers. Is he an early champion of women’s independence? Over the years, some critics have hailed him for this, while others have condemned him for objectifying women and revealing his own insecurities.

“Star Burlesque” is a complicated painting of shared emptiness, empty even of the sources of its emptiness. Its meaning is intangible; you supply it according to your imagination and your experience. That’s a good piece of art, in my book.

My favorite part of the exhibit is the juxtaposition of two other paintings, both concerning dancing. Marsh haunted dance halls for inspiration, and one of his best works springs from one of the most famous clubs.

It’s “Harlem, Tuesday Night at Savoy” (1932), in which a multiracial clientele is jumbled up on the dance floor, energized like a roaring fireplace. The colors are fiery, too. The women’s dresses, hemlines frothing above their knees, are bright yellow, red and orange, with more demure folks at the margins in cool lavender and green. At the center is a black woman with terrific physical grace; every joint is torqued, and a quickening rhythm runs from her shoulders to her narrow waist and down to thin calves, smartly crossed, and high-heel feet that are pointed away from us.

The Savoy offered physical release, as is evident from the tangle of moving bodies around this woman, some of them kicking legs into the air. But its joy was fleeting. The faces in this painting are inscrutable, or crazed, delirious. As in the beach paintings, the cork has flown off the participants’ bottled-up spirits, suppressed over the workweek. But the body of that central woman is in a twist, telling us the tension of the times is unrelieved even in the off-hours.

Still, I’d rather be at the Savoy than in the world of “Zeke Youngblood’s Dance Marathon” (1932), on the opposite wall. Here are similar bright colors, but the centerpiece is exhaustion. The female competitors in this cruel contest have stout, sturdy legs, but two of them are slumped against their partners, asleep on their feet.

The dancers in “Savoy” face us; in “Marathon” they turn their backs on us. Marsh, chronicler of common people, puts the spectator in the position of the ticket-holders to these gladiator-style events in which folks endured days, even weeks, on their feet for a cash prize. It’s an uncomfortable perch.

“Swing Time” includes some of Marsh’s photographs, along with his drawings and prints, and works by fellow American scene artists such as Isabel Bishop, Walker Evans and Kenneth Hayes Miller. There are snippets from a film documentary of life in the 1930s: rows of women at typewriters, people standing at lunch counters. A customer accidentally sloshes some coffee into his saucer; he tips the contents back into his cup, so as not to waste a drop. One man tosses a newspaper into a wire trash bin on the street; another pulls it out to read.

It all makes for a rich, nuanced context for Marsh’s paintings. But they leave a singularly powerful impression, because he used the era’s bodies to tell its stories.

“Swing Time: Reginald Marsh and Thirties New York”

runs through Sept. 1 at the New-York Historical Society Museum and Library