Pregnant pop superstar Beyonce heads into the Grammy awards tonight aiming to clinch her first album of the year win, while riding high on a wave of goodwill that greeted her surprise announcement that she was expecting twins.

The biggest night in the music industry is expected to mark her first public appearance since the 35-year-old singer announced her pregnancy on February 1 with a message and an elaborate photo shoot proudly displaying her baby bump that broke social media records.

In a live show as much about spectacle as trophies, Beyonce's appearance on the Grammy stage has not been officially confirmed. But celebrity website TMZ said the Formation singer, known for her high energy dance performances, had been seen rehearsing in Los Angeles for the show last week.

Other performers at the three-hour show include Katy Perry, Lady Gaga, The Weeknd, Bruno Mars, Adele, Demi Lovato, best new artist nominee Chance the Rapper, A Tribe Called Quest, Carrie Underwood, Alicia Keys and album of the year Americana music nominee, Sturgill Simpson.

Beyonce has a leading nine Grammy nods for Lemonade, her powerful visual album about race, feminism, betrayal and empowerment.

The R&B singer will compete head on with Britain's Adele, the only other artist to be nominated for all three top awards - album, song and record of the year - for her comeback release 25.

But the 2017 Grammys will also be as much about absent friends as those taking part in Sunday's show.

Tributes are planned for music greats Prince and George Michael, both of whom died unexpectedly in 2016. David Bowie, who died in January 2016, was celebrated at last year's Grammys and his final album Blackstar is up for four Grammys.

Some of music's biggest current acts will also be missing.

Frank Ocean didn't submit his critically acclaimed Blonde for Grammy consideration because he considers the organisation out of touch with young black artists; Justin Bieber, in the best album race for Purpose, and Kanye West, who has kept a low profile since a mental health crisis last fall, are not expected to attend for similar reasons despite multiple nominations; and Canadian rapper Drake, whose Views was the biggest selling album worldwide in 2016, and who has eight Grammy nominations, is on tour in England.

In an awards season full of fiery political speeches and protests against the policies of President Donald Trump, some winners might use the Grammy stage to drive their points home.

James Corden, best known for his viral Carpool Karaoke segments with leading singers, will host the show but has pledged not to sing himself.