Herb Jeffries, a jazz balladeer whose matinee-idol looks won him fame in the late 1930s as the “Bronze Buckaroo” — the first singing star of all-black cowboy movies for segregated audiences — died May 25 at a hospital in West Hills, Calif. He was widely believed to be 100, but for years he insisted he was much older.

The cause was stomach and heart ailments, said Raymond Strait, a friend of 70 years who had been working with Mr. Jeffries on his autobiography. Mr. Jeffries liked to exaggerate his age to shock listeners. “He wanted people to say, ‘Wow, he can still sing pretty good for 111,’ ” Strait said.

Mr. Jeffries had a seven-decade career on film, television, record and in nightclubs. His baritone voice — extraordinarily rich but delicate — was memorably captured on his greatest musical success, a 1941 hit recording of “Flamingo” with Duke Ellington’s big band.

With a towering physique and a square jaw, Mr. Jeffries was perfectly suited to capitalize on the singing-cowboy movie craze that Gene Autry and Roy Rogers popularized in the 1930s.

Black performers such as the rodeo star Bill Pickett had appeared in silent westerns, but the Stetson-sporting, six-gun-toting Mr. Jeffries inaugurated the concept of a black singer riding in the saddle as the hero.

Herb Jeffries, the first singing star of all-black cowboy movies for segregated audiences, died May 25 in West Hills, Calif. (Courtesy of The National Cowboy and Western Heritage Museum, Okla.)

Sometimes billed as Herbert Jeffrey, he starred in a cluster of low-budget “race” pictures in the late 1930s: “Harlem on the Prairie,” “Rhythm Rodeo,” “Two-Gun Man from Harlem,” “The Bronze Buckaroo” and “Harlem Rides the Range.”

His recurring character in several of the films was Bob Blake, a debonair man of the range with a passion for justice and song.

His sidekicks included comedian Spencer Williams Jr., later known for his work as Andy on CBS’s “Amos ’n’ Andy” television show. His backup singers were the Four Blackbirds, also known as the Four Tones. For background characters, he said, he borrowed black actors who had been “Tarzan” movie extras.

Mr. Jeffries learned to ride on his grandfather's dairy farm in Port Huron, Mich., and he had grown up loving the cowboy films of Tom Mix and Buck Jones. He said the idea for an all-black cowboy picture came to him while touring the South as a singer in the mid-1930s and visiting tin-roof movie theaters meant for black audiences.

He had spent fruitless years trying to convince black backers — including millionaire numbers runners — that African Americans would spend money on cowboy pictures featuring people of their own color.

As a last resort, Mr. Jeffries persuaded producer Jed Buell — best known for making the all-midget western musical “The Terror of Tiny Town” (1938) — to finance the movies.

At first, he said, Buell was hesitant to cast Mr. Jeffries because of his light skin.

“I asked him, ‘What do you want, someone who can ride and sing and act, or a color?’ ” Mr. Jeffries told the Washington Times in 2003. “I called Buell’s attention to a picture called ‘The Good Earth,’ where Paul Muni and Luise Rainer had passed as Chinese peasants.

“I challenged him: ‘Darken me up if you want to. And I'll keep my hat on tight so no one can see my hair.’ In desperation, he said yes.”

Neither had any illusion about the films’ quality. Many rehashed the plots of low-grade westerns starring white actors. Mr. Jeffries later called his movies, some filmed on a black dude ranch near Victorville, Calif., “the first bunch of C-minus westerns.”

Yet he was sentimentally attached to them. Starting in the 1980s, they contributed to a revival of interest in his career.

In 1995, he sang on a CD called “The Bronze Buckaroo (Rides Again)” that reprised “I'm a Happy Cowboy” and other songs from his movies. The release paired him with an usual assortment of entertainers, including the Mills Brothers, Take 6 and “Barney Miller” star Hal Linden on clarinet.

Mr. Jeffries was coy about his background. He claimed, at times, to have been born Umberto Alejandro Balentino to an Irish mother and Sicilian father of mixed race. Other sources say he was born Herbert Ironton Jeffries in Detroit, probably on Sept. 24, 1913 — the date Strait said was correct. Other reported dates of birth range from 1909 to 1916.

He told the Atlanta Journal-Constitution in 2008 of his heritage: “I’m all colors, like everyone else. If we all go back 10 or 15 generations, we don’t know what we have in us. I don’t think there’s one person from around the Mediterranean who doesn’t have Moorish blood. I have Sicilian blood, and I have Moorish blood. I am colored, and I love it. I have a right to identify myself the way I do and if nobody likes it, what are they going to do? Kill my career?”

Mr. Jeffries never knew his father. He was raised by his mother in a boardinghouse she ran and where many singers and actors stayed. It was this exposure to show business that led Mr. Jeffries to appear, as a young man, in Detroit nightclubs and ballrooms.

In 1933, he joined up with pianist Earl “Fatha” Hines’s orchestra at the Chicago World’s Fair and spent the next two years with the band on tour.

Afterward, he began vigorously pursuing a career in Hollywood as an actor, editor and songwriter. On the cowboy films, he performed most of the stunts himself and was continuously aching.

To sell the movies, Mr. Jeffries said, he would go to black theaters and do rope tricks and sing with a backup group. As the market for race pictures was waning, he said, he “went home to Detroit to show off my ego.”

In Detroit, he drove up to a Duke Ellington band concert in a Cadillac with steer horns on the hood. Inside the ballroom, he said, Ellington could not help but notice him in his cowboy regalia and invited him to sing with the band. Soon, billed as the Bronze Buckaroo as an homage to his movie fame, he became the band's first male vocalist.

He cut several records with the Ellington band in the early 1940s, including “Flamingo,” “Jump For Joy,” “You, You Darling” and “Brown Skin Gal in a Calico Gown.” In Los Angeles, he also appeared in an Ellington stage musical about racism called “Jump for Joy” starring Dorothy Dandridge. Mr. Jeffries said one of the show’s backers, movie actor John Garfield, told him to darken his skin because of concerns he would look too white next to Dandridge.

“Now I’m onstage,” he said. “Duke is furious. He says, ‘What are you trying to do — an Al Jolson?' I tried to explain. But Duke stormed out and had a little talk with the producers. I never darkened up again.”

After Army service in World War II, he spent about a decade in France operating supper clubs in Paris and on the Riviera. He settled in Los Angeles in the early 1960s, and he remained active as a singer in clubs, theaters and cruise ships, usually with an Ellington repertoire.

He also appeared several times on the TV police drama “Hawaii Five-O” and in westerns such as “The Virginian.” He had a supporting role in the Jack Palace western film “Portrait of a Hitman” (1977).

The rediscovery of his old movies in the mid-1980s renewed interest in the role of black cowboys, and he emerged as a commentator on the topic. In 2004, he was inducted into the Oklahoma-based Hall of Great Western Performers.

Mr. Jeffries said he was a devotee of Eastern religions and meditated every morning and night “to attune to the frequency.” He had five marriages, including one to exotic dancer Tempest Storm, whom he directed in a 1967 sexploitation horror film called “Mundo Depravados.” Survivors include his wife, the former Sarah Lee “Savannah” Shippen, and five children.