The Nicholas Brothers, showing what stepping can be. The Nicholas Brothers, showing what stepping can be.

Fans of the Nicholas Brothers — a tap-dancing duo who once enjoyed worldwide fame — included Gene Kelly, Fred Astaire, Mikhail Baryshnikov and Gregory Hines. But mention the brothers to most people today and you’ll get a blank look.

“Unlike Fred Astaire or Gene Kelly, they’re not the stars of any movies,” says Bruce Goldstein, director of repertory programming at New York’s Film Forum. On Saturday, Goldstein will present a talk titled “The Nicholas Brothers: Born to Dance” at the National Gallery. He’ll mix his own expertise (Goldstein, a friend of the late Harold and Fayard Nicholas, directed a documentary about them) with archival footage and scenes from their Hollywood work.

In the 1940s and ’50s, the brothers had no problem being recognized, even if they didn’t carry any films. “They just appeared in what was called the ‘specialty number,’ ” Goldstein says, referring to a dance number inserted into a film to add spectacle rather than to advance the plot.

Spectacle was what the Nicholases did best; though primarily tap dancers, they specialized in unconventional flips, leaps and splits. The African-American brothers started as child performers in the 1920s, hitting it big when they began appearing at the Cotton Club in New York in 1932. It was 1940’s “Down Argentine Way” that launched the brothers to international fame and led to them becoming contract players in Hollywood, which in turn led to their plum appearance in “The Pirate.” That 1948 film, Goldstein says, featured the first interracial dance routine, “if you don’t count Shirley Temple and Bill Robinson.”

While it would be easy to make an engaging program just by showing the brothers’ high-energy dance routines, the clips can be exhausting for an audience. “You can’t really look at all the musical numbers right after another,” says Goldstein, who mixes in rare home movies. “I intersperse to give a breather.”

Goldstein, who is on the national preservation board for the Library of Congress, nominated the brothers’ home movies for preservation in 2011, he says. “I brought the sample to the board meeting and everyone flipped. It’s the most amazing historical document, not only of life in Hollywood in the ’30s, but African-American life in Hollywood in the ’30s, which is totally rare.”

Even though the Nicholas Brothers never achieved the level of fame that Kelly and Astaire did, they were a box-office draw and respected by their peers. “Donald O’Connor once called them the greatest dancers of all time,” Goldstein says. “He didn’t say ‘tap dancers’ or ‘specialty dancers.’ For a black act of that period, they went to the very top. They went as far as they could go.”

National Gallery of Art, East Building, 4th Street and Constitution Avenue NW; Sat., 2:30 p.m., free; 202-737-4215. (Archives)