NEW YORK — Marguerite Piazza had a voice that could pack a concert hall and a figure that transfixed television audiences. She was sought out for ribbon cuttings and commercial endorsements and once performed as part of a Super Bowl halftime show.

She was a pop star, in other words, just one among the ever-changing panoply that graces the glossies, except that she gained fame for singing opera.

Ms. Piazza, who at the pinnacle of her career in the 1950s performed with the Metropolitan Opera, died of heart failure Thursday at her home in Memphis, her daughter Marguerite Bonnett said. She was 86.

Her life and career evoke an era when the gap between pop culture and high art was more easily bridged, when what audiences watched on television was similar to what they saw at the theater or concert hall.

“I can’t say that I like television more than opera because I do opera on television,” Ms. ­Piazza said in a May 1951 interview with The New York Post.

Marguerite Claire Luft was born in New Orleans. She attended fine arts programs at Loyola University and Louisiana State University before taking off to pursue her dream in New York, where her teacher suggested she adopt her mother’s maiden name, Piazza, because he thought an Italian-­sounding name would boost her operatic credibility.

She began her career on radio, but moved into television in its earliest days, where both her good looks and her soaring soprano quickly made her a star. In the early 1950s, she performed opera and other music on “Your Show of Shows,” the popular variety program that made Sid Caesar a star.

Only after she had become a television success did she appear at the Metropolitan Opera, where in 1951 she had 14 performances as Rosalinde in “Die Fledermaus.”

Then she traded ball gowns for cocktail dresses and joined the supper-club circuit, performing jazz and pop in spots including the Plaza in New York, the Cocoanut Grove in Los Angeles, and the Sands in Las Vegas. She performed in the nightclubs of Havana before Fidel Castro came to power.

Along the way, she appeared in commercials. “I find Camels have a mildness that agrees with my throat,” a bejeweled Ms. Piazza said in a cigarette commercial in the 1950s.

Bloomingdale’s once invited her to be a celebrity chef for free cooking classes it offered at its New York location. And she joined other New Orleans performers in the halftime show at Super Bowl IV there in 1970. Her career came to an end when she was diagnosed with cancer in the 1970s. She ­remained active in charities and as a patron of the arts, particularly in her adopted hometown, ­Memphis, where she had lived off and on since the 1950s.

Ms. Piazza was married four times. She and her first husband, Karl Kritz, a former assistant conductor at the Met, were divorced. Ms. Piazza was widowed three times. Besides her daughter Marguerite, she leaves two other daughters; two sons; and seven grandchildren.