“You know, you’re still a very beautiful woman,” my stepson, Felipe, a newly-minted Marine, told Anna Moffo at our apartment six years ago. Though Anna had been undergoing chemotherapy, as she did almost continuously in her 10-year battle with cancer, she did look radiant that evening, and she never forgot Felipe’s remarks. Right up until her death last week at age 73, she’d ask my wife or me: “How’s my Marine?”

Moffo was born with extraordinary beauty, intellect and talent. That’s what made her a great artist. But her Italian-American shoemaker father also instilled in her enormous pride and discipline. That’s what made her an inspirational and steadfast friend. It’s also what kept her alive and productive right up until her death.

Anna was so much more than a voice with a beautiful face, arguably the most beautiful face in modern opera. She began her schooling in viola and piano as well as voice, for which she received a full scholarship to Curtis Institute. While her voice was not as powerful as, say, that of Maria Callas, it had enormous depth and was laced with extraordinary richness.

Soon after Curtis came a Fulbright Scholarship for study in Rome. She premiered as Norina in Donizetti’s “Don Pasquale” in Spoleto. The year after that, 1956, Anna achieved fame by staring in a television production of Puccini’s “Madama Butterfly.” She married the director, Mario Lanfranchi, a year later.

Her new husband was an overbearing, Svengali-like figure, who acted as Anna’s agent and pushed her hard – some (including Anna) say too hard. For about a decade her voice held up as Lanfranchi booked her everywhere he could, at opera houses, on television, in films, at benefits. She scored points quickly in America, particularly when she arrived at New York’s Metropolitan Opera House in 1959 to play Violetta in “La Traviata,” a role she would repeat at the Met 80 times over the years. This record was second only to the 86 performances of Violetta by the soprano Licia Albanese.

I happened to see the legendary Mme. Albanese at the funeral home where Anna was laid out on Monday evening. Even at 93, Mme. Albanese was full of sparkle. She said that on stage Anna “had everything, voice, beauty and acting. She had more feeling on stage than anyone I’ve seen.”

Anna became America’s favorite opera star, appearing on the “Bell Telephone Hour,” Ed Sullivan and other telecasts. She made opera approachable for most Americans, and she was coming into her own with the critics when, in the early 1970s, her voice suddenly weakened due to overuse. She never made a full comeback.

The break in her voice coincided with the breakup of her first marriage, dissolved in 1972. Two years later she married RCA scion Robert W. Sarnoff. He used his considerable power as head of RCA to try to revitalize her career, but Anna’s voice did not match the campaign her new husband constructed for her.

Whether it was her beauty, or her relationship with Sarnoff, critics seemed to take a certain joy in knocking her down, needlessly chiding Anna even into her death. Opera critic Anthony Tommasini, quoted in the New York Times obituary, called her voice “unreliable” and “poor,” adding only a backhanded compliment: “For a brief time, though, Ms. Moffo was a lovely singer and appealing artist who broke out of the traditional career mode to reach the larger public.” The review infuriated Mme. Albanese, who complained, “This was not only an insult to Anna, but an insult to opera.”

Anna’s last public appearance was just two months ago, to pay tribute to the 92-year old Mezzo-soprano, Rise Stevens. “Although her increasing need to conserve her energy was apparent to her colleagues backstage,” wrote Opera News, “once she stepped up to the podium Moffo was vibrant, gracious and wryly funny – the definition of a total professional and a real beauty.” Just as my stepson the Marine and all who knew her understood all along.

The funeral is at 10 a.m. today, at St. Patrick’s Cathedral.

Mr. Asman is host of “Forbes on Fox.”