She died of respiratory failure not related to COVID-19, according to a representative, Jason Lee. Her husband was at her bedside when she died on Saturday.

The Bergmans, who married in 1958, were among the most enduring, successful and productive songwriting partnerships, specialising in introspective ballades for film, television and the stage that combined the romance of Tin Pan Alley with the polish of contemporary pop.

They worked with some of the world's top melodists, including Marvin Hamlisch, Cy Coleman and Michel Legrand, and were covered by some of the world's greatest singers, from Frank Sinatra and Barbra Streisand to Aretha Franklin and Michael Jackson.

"If one really is serious about wanting to write songs that are original, that really speak to people, you have to feel like you created something that wasn't there before -- which is the ultimate accomplishment, isn't it?" Marilyn Bergman told The Huffington Post in 2013.

"And to make something that wasn't there before, you have to know what came before you."

Their songs included the sentimental Streisand-Neil Diamond duet You Don't Bring Me Flowers, Sinatra's snappy Nice 'n' Easy and Dean Martin's dreamy Sleep Warm. They helped write the uptempo themes to the 1970s sitcoms Maude and Good Times and collaborated on words and music for the 1978 Broadway show Ballroom.

But they were best known for their contributions to films, turning out themes sometimes remembered more than the movies themselves. Among the highlights: Stephen Bishop's It Might Be You, from Tootsie; Noel Harrison's The Windmills of Your Mind, from The Thomas Crown Affair; and, for Best Friends, the James Ingram-Patti Austin duet How Do You Keep the Music Playing?

Their peak was The Way We Were, from the Streisand-Robert Redford romantic drama of the same name.

Set to Hamlisch's moody, pensive melody with Streisand's voice, it was the top-selling song of 1974 and an instant standard, proof that well into the rock era, the public still embraced an old-fashioned ballad.

The Bergmans won three Oscars -- for The Way We Were, Windmills of Your Mind and the soundtrack to Streisand's Yentl -- and received 16 nominations, three of them in 1983 alone. They also won two Grammys and four Emmys and were inducted into the Songwriters Hall of Fame.

Fellow composer Quincy Jones called news of her death crushing. "You, along with your beloved Alan, were the epitome of Nadia Boulanger's belief that 'an artist can never be more or less than they are as a human being,'" he tweeted.

Streisand on Saturday posted a picture of herself with the Bergmans on Twitter, saying they were like family, as well as brilliant lyricists.

"We met over 60 years ago backstage at a little nightclub, and never stopped loving each other and working together," Streisand wrote.

Their songs are timeless, and so is our love. May she rest in peace."

Australian Associated Press