Fame can have a tipping point, that moment where reputation obscures and even subsumes the person behind it.

That certainly happened to Maria Callas, the diva’s diva, as notorious for her artistic temperament and most famous lover, and her outspokenness about both, as she was for her singing.

The Greek-American soprano was an exemplar of “bel canto” singing whose storied career was filled with live performances and studio recordings, most made before the technology that could allow her to be captured, in song, in her unadulterated digital glory.

Aficionados who glory in her art are fewer in number, and great sopranos have come along in the 40 years since her death who push her further into the recesses of legend.

“Maria by Callas” rescues from that “Well, she was great for her time” indifference.

Actor turned documentary director Tom Volf immersed himself in her in her letters and in the public film and video record, voluminous because she spent decades in the public eye, was never interview-shy and was hounded by the press almost everywhere she went, from the early 1950s until her death in the 1970s.

She was, she says in the most extensively quoted interview here, a 1960s talk with David Frost (of “Frost/Nixon”), always Maria, but “the Callas I have to live up to.”

Her posh pan-European accent, part affectation but mostly acquired from learning her art in Greece (she was born in New York) and performing in and living in Europe for most of her life, beautifully sets up the reminiscence that Volf’s film is.

This was an age when “high culture” wasn’t a dirty phrase, when people either knew the difference between great art and accomplished artists and junk culture and pop stars, or aspired to know. Callas became one of the most famous women of her time on the strength of her talent and training.

And when she felt, for reasons she explained and sound perfectly reasonable in her own words — the film is almost wholly limited to her words, her version of events — that she could not perform, could not honor a commitment or continue a performance (onsets of illness, etc.), she came under assault from the culture-covering press of the day.

Volf shows us long walk-and-talk interview — chases really – as Callas emerged from airplanes in those pre-jet, pre-jet bridge boarding gates. She smiled, even when she was firmly and politely insisting “I will answer no questions at this time,” badgered by reporters of many nationalities and of every medium of the day, captured on film as strode, without bodyguards, to a waiting limo.

The genteel interview style of her era is exemplified by Edward R. Murrow’s celebrity interview show, “See it Now.” But even Frost and near the end of Callas’s life, Barbara Walters, as they approached touchier subject matter, knew how to question someone with respect, even when asking about her years-long separation (divorce not being legal in the Catholic theocracy of Italy) from her husband and her relationship with shipping magnate Aristotle Onassis.

Questioned in English or French, Callas didn’t dodge the queries, occasionally allowing a faint flash of temper (her feud with Metropolitan Opera director Rudolph Bing could set her off), often returning to the story of how her mother and later others “forced” her into singing, how she felt true happiness was only available to women who married and had children and how her “art” and her “destiny” precluded that.

She made her glittering life seem tragic, even as she denied her own right to feel sorry for herself thanks to everything her gift and her “destiny” gave her.

No wonder she became a gay icon. Any doubt about that and her place on a pedestal that has included Judy, Barbra and others, is wiped away by on-the-street 1960s interviews with effeminate young men standing in line to grab tickets to a performance at the Met.

But what also distinguishes Volf’s fine film (he wrote a book on her as he was researching the movie) is the way he treats her on-stage life. There’s plenty of grainy footage — home movie quality — of her early stardom, some of it surely captured during dress rehearsals –underscored with hissing tape recordings of Callas in “Norma” “Tosca” or “Carmen.”

And then there are her command performances, concerts without the costumes but with all the theatricality of her onstage presence. They are jaw-dropping marvels, and Volf lets each songs play out in its entirety. No studio gimmicks, no microphone to amplify her –just Callas, perfect tone, perfect pitch, absolute control, making that stunning, almost unworldly sound with just her lungs and voice, and reaching the back row as she did.

It seems inhuman until you hear and see her playfully vamp through the “Habanera” (“L’ amour est un oiseau rebelle”) from Bizet’s “Carmen.”

And at the end, no bows, the rare kiss blown at a particularly enthusiastic audience, she was “embarrassed,” she suggests,whenever adored.

Volf breaks no real new ground on her biography, much chewed-over by others — moving to Greece on the eve of World War II to receive her training, marrying an older Italian industrialist who craved a share of her fame, taking up with Onassis who perhaps had the same designs.

She was so near-sighted that she couldn’t see much while onstage, and wasn’t so much born to bel canto as trained into her by a Spanish singer and teacher in Greece — Elvira de Hidalgo (an old TV interview with her is included).

It’s the product of that training that is the heart of “Maria by Callas,” that voice rescued from historical notoriety, that performing style celebrated and that woman, cultivated and refined, brought back from the dead and the dismissed. With her own words and her own singing, Volf invites us to savor Callas as she saw herself, and lets the evidence of that once-in-an-epoch voice back her up.

MPAA Rating: PG for mild thematic elements, some smoking and brief language

Cast: Maria Callas, David Frost, Edward R. Murrow

Credits:Directed by Tom Volf. A Sony Pictures Classics release.

Running time: 1:53