Fayard Nicholas, who amazed audiences with gravity-defying dance steps and supremely skilled tap dancing as part of the Nicholas Brothers dance duo, died Jan. 24 at his home in Toluca Lake, Calif., from the effects of a stroke suffered in November. He was 91.

Mr. Nicholas and his younger brother, Harold, who were completely self-taught, demonstrated their astonishing moves in nightclubs, theaters and movies in the 1930s and '40s. They leapt over each other, tap-danced on one foot, ran up walls, did back flips and leapt high in the air to land in splits, all the while looking supremely elegant and relaxed.

"The things they did were beyond our scope and anyone's scope since," the late dancer Gregory Hines told The Washington Post in 1991, when the brothers received Kennedy Center Honors.

The Nicholas Brothers appeared in about 30 movies and were talented singers and actors as well as dancers, but Jim Crow customs kept them from having speaking parts, let alone starring roles. Still, their acrobatic dance segments often upstaged the performances of the movies' better-known stars.

Fayard Nicholas, more than six years older than his brother, who died in 2000, was considered the stronger dancer and choreographed many of their routines. The brothers made their debut in 1928, and four years later were appearing at New York's Cotton Club, where leading black acts performed for white audiences.

With occasional detours to other venues, the brothers headlined at the Cotton Club for eight years. They made their Broadway debut in "The Ziegfeld Follies of 1936," toured Europe the same year and were back on Broadway in "Babes in Arms" in 1937, with choreography by George Balanchine.

Their appearance in "Down Argentine Way," a 1940 film with Betty Grable and Don Ameche, was so wildly successful that some theater operators rewound the film to show the brothers' dance segment a second time. They were rewarded with a five-year contract from Twentieth Century-Fox.

In "Orchestra Wives" (1942), the brothers accomplished one of their most extraordinary effects by running two steps up a wall, doing a back flip and landing in a split, without using their hands for balance. They executed the maneuver on the first take.

Performing with an all-black cast that included Lena Horne and Bill "Bojangles" Robinson in "Stormy Weather" (1943), the brothers leapfrogged each other down a staircase, landing in splits, then dashed up the stairs to slide down a ramp in splits. Fred Astaire called it the greatest musical dance number he had ever seen.

"Some people think we're a flash act," Fayard Nicholas told The Post in 1991. "But we're not. At the end of the act, we'd put those splits in, but we'd do them gracefully. You don't just hit, bam and jump up. We tried to make it look easy. It's not easy."

Fayard Antonio Nicholas was born Oct. 20, 1914, in Mobile, Ala. His father was a drummer and his mother a pianist, and the parents moved often to lead orchestras on the black vaudeville circuit. After the family settled in Philadelphia, Mr. Nicholas spent much of his childhood studying well-known dancers, particularly Robinson.

"Every day after school I would go to the Standard Theater and find a seat as close to where my father was playing drums as possible," he told the Los Angeles Times in 1985. "Just by watching, I taught myself to dance."

By age 13, Mr. Nicholas had taught his brother to dance, and the two worked up an act.

"We started doing all these different routines, just having fun," he recalled. "And my parents looked at each other and said, 'Hey, we've got something here.' "

Both brothers were small and lithe -- Fayard was 5-feet-4, Harold 5-feet-2 -- and stood out from other dancers with their smoothness, the graceful use of their hands and by never looking at their feet.

"My brother and I used our whole bodies, our hands, our personalities and everything," Mr. Nicholas said. "We called our type of dancing classical tap and we just hoped the audience liked it."

"Fayard Nicholas changed the face of tap dancing," said Rusty E. Frank, author of "Tap: The Greatest Tap Dance Stars and Their Stories, 1900-1955." "Nobody has ever done what he and his brother did."

The brothers made their last movie together in 1948, performing a number with Gene Kelly in "The Pirate." They spent much of the 1950s in Europe before going their separate ways. Mr. Nicholas had a role in the 1970 racial drama "The Liberation of L.B. Jones."

The brothers were rediscovered in the 1970s when some of their dance scenes were included in the "That's Entertainment" films, which were compilations of memorable moments from MGM musicals. They occasionally performed together until the 1990s. In 1989, Fayard Nicholas received a Tony award for his choreography of the Broadway revue "Black and Blue."

In the 1996 musical "Bring in da Noise, Bring in da Funk," playwright and director George C. Wolfe angered the brothers by calling a tap-dance team obviously based on them "Grin & Flash."

"Why would they try to bring down the pioneers who made it possible to do what they're doing today?" Mr. Nicholas told The Post. "They should say, 'Thank you.' "

His marriage to Geraldine Nicholas ended in divorce. His second wife, Barbara January, died in 1997 after 30 years of marriage.

Survivors include Mr. Nicholas's wife, Katherine Hopkins-Nicholas, whom he married in 2000; two sons from his first marriage; a stepdaughter from his second marriage; a sister; and four grandchildren. Two of his granddaughters now appear as the Nicholas Sisters, dancing updated versions of the brothers' routines.

Mr. Nicholas continued to perform occasionally until shortly before his stroke. In one of his final interviews last year, he said: "I loved dancing with my brother. I miss him. We did everything together."