The night's most memorable performance came from P!nk who dangled off the edge of a 54-story building.
Diana Ross gets lifetime achievement at American Music Awards on night of divas
Bruno Mars took the top prize at the American Music Awards on Sunday at a show that paid glowing tribute to legendary divas Diana Ross and the late Whitney Houston.
Mars, the retro star who found fresh success with the funky beats and R&B harmonies of his latest album 24K Magic, accepted Artist of the Year with a brief but enthusiastic speech recorded in a moving minivan, as Mars explained he was travelling.
Unveiled at a made-for-television gala in Los Angeles, the American Music Awards select winners based on fan voting, unlike the more prestigious Grammys which are decided by professionals.
The awards presented a lifetime achievement award to 73-year-old Ross, the towering voice of Motown, who ended the show with a medley of her hits starting with anthem I'm Coming Out.
Ross - whose daughter, Black-ish television series star Tracee Ellis Ross, was the awards' host - was introduced by a video from Barack and Michelle Obama, with the former president revealing that the Motown great's music was still frequently on rotation at their post-White House home.
The awards also honoured Houston to mark 25 years since her blockbuster film and soundtrack The Bodyguard, which featured her classic cover of Dolly Parton's I Will Always Love You.
Houston, 48, was found dead in her hotel bathroom in February 2012 on the eve of the Grammy Awards. A coroner ruled that she died of accidental drowning, with cocaine and heart disease listed as contributing factors.
Christina Aguilera signed up for the daunting task of doing justice to Houston and reached the high notes with flair despite briefly veering off-key.
But the night's most memorable performance came from P!nk who dangled off the edge of a 54-story building.
P!nk, singing Beautiful Trauma on a headset, was attached by rope to a high floor of the LA Live hotel and entertainment complex as she slid acrobatically with dancers on her side and above.
Pleas for tolerance
The broadcast switched to Washington where Lady Gaga was putting on an intricately choreographed performance of The Cure with pyrotechnics raining from above. Her concert was later interrupted as she was told she won Favorite Female Artist.
A visibly moved Gaga thanked fans and voiced her familiar plea for tolerance, saying, "Remember that if you feel different or you feel not understood, don't you dare give up."
Tracee Ellis Ross had said the awards were showcasing "earth-shattering, groundbreaking women." But the focus came after criticism that the awards for the first time had no women in contention for Artist of the Year, despite the national spotlight on sexism in the entertainment industry.
At a time of intense tensions in the United States, the show began with a call against violence and hate but avoided overt mentions of President Donald Trump.
The awards opened with a tribute on politically safe ground -- honouring first responders to emergencies across the United States.
P!nk - on the ground rather than above - and Kelly Clarkson serenaded assembled first responders with a cover of R.E.M.'s Everybody Hurts, a track off the rockers' influential Automatic for the People album which came out 25 years ago last month.
In one of the show's most poignant moments, the award for alternative rock act went to Linkin Park, whose frontman Chester Bennington killed himself in July after years of struggling with depression and substance abuse.
To a standing ovation, bandmate Mike Shinoda dedicated the prize to Bennington.
"All of you tonight, whether you're a fan or an artist, I want you to take a moment to appreciate what you've got and make Chester proud," he said.