Though less generous towards the film as a whole, the New York Times‘ Vincent Camby raved about Ross. “She’s an actress of exceptional beauty and wit, who is very much involved in trying to make a bad movie work,” he wrote.

Black audiences flocked to the movie and music fans couldn’t get enough of the highly-acclaimed soundtrack — which topped the Billboard charts and eventually sold 2 million copies.

Williams and Ross arguably became Hollywood’s first truly bankable black romantic big screen duo, on par with the likes of Bogie and Bacall and Tracy and Hepburn.

“The chemistry that the two of you had on screen was like something we had never seen before. Was that real for you?” Oprah Winfrey asked Williams during a special edition of her talk show that commemorated the 35th anniversary of the film’s release.

“Oh, absolutely,” Williams said, adding that his most cherished memory of working with Ross was “her mouth.”

Williams was accessible as a sex symbol in a way that his predecessors, like Sidney Poitier and Harry Belafonte, could never be. He and Ross would be paired again in the campy romantic film Mahogany, which was another hit at the box office.

For Richard Pryor fans, the film was something of a revelation. Already a breakout star in the world of stand up comedy, he had yet to make a major splash in films. Pryor would become a box office juggernaut in a few years with his smash pairings alongside Gene Wilder (Silver Streak and Stir Crazy), but his heartbreaking performance as the drug addled “Piano Man” in Lady Sings the Blues conveyed a depth that unfortunately went unexploited in later films — with the notable exception of Paul Schrader’s criminally underrated 1978 film Blue Collar.

The specially designed Bob Mackie costumes created a sensation of their own. Stylish black women started sporting Ross’s signature gardenia in their hair and the movie reaffirmed the pop star’s place in the fashion world as a trendsetting idol.

The costumes, music, set decoration, screenplay and, most importantly, Diana Ross, were all nominated for Academy Awards.

The Oscars that year were historic for African-Americans. For the first time ever (and the last time until 2004) multiple black actors were nominated for lead roles. Diana Ross was up against Cicely Tyson for best actress in another triumphant black-themed 1972 film Sounder. And the late Paul Winfield competed against the likes of Marlon Brando for his lead role in that same picture.

Although Tyson, Winfield and Ross all went home empty-handed that night, there was every reason to believe black movies were on an upswing. Yet, for the most part, blaxploitation films largely dominated the marketplace for the rest of the decade.

Sadly, Motown’s investment in the movies was short lived. Their brief Hollywood run provided cult classics like Mahogany, The Wiz and The Last Dragon — but none of these films matched the commercial and critical success of Lady Sings the Blues. After receiving scathing reviews for her performance in The Wiz, Ross dropped out of the film business altogether.

“The work of it—the acting part, using your imagination—that was good,” Ross later said about making movies. “But the waiting and the sitting? I found that, really, I wanted to be with my kids and not sitting in a trailer somewhere.”

As for Lady Sings the Blues, its legacy remains mixed in some audiences’ eyes. More modern reviews of the film have not been kind.

Lady Sings The Blues incongruously transforms Holiday’s messy, bisexual, masochistic romantic history into a glossy romance about a troubled, needy woman-child and the endlessly patient dreamboat who could slow but never entirely halt her march toward self-destruction,” wrote Nathan Rabin of The Onion AV Club.

Meanwhile, the current controversy surrounding the purported casting of the fair-skinned Zoe Saldana as the late dark-skinned songstress Nina Simone has drawn comparisons to initial outcry over Ross’s casting as Holiday.

Still, after forty years, while the movie is somewhat dated, it does provide us with a glamorous time capsule.

Lady Sings the Blues captures Motown at its pinnacle and showcases a caliber of stars rarely seen in black film. The music and story still have the power to make audiences swoon and cry.

Follow Adam Howard on Twitter at @at_howard