"We will never break/ Built on a foundation/ Strong enough to stay/ We will never break," sang the star, holding back tears. "As the water rises/ And the mountains shake/ Our love will remain."
Clad in a white suit, Legend sat center stage where he played the piano throughout the performance. Afterwards, host Kelly Clarkson shared her support for Legend and Teigen, telling her fellow Voice coach she was sending "all my love to you and Chrissy."
"I want to take a moment to talk about a friend who inspires me on the daily," Clarkson said. "Not only as a musician, a songwriter, but as a human. John Legend is one of my favorite people on this planet and it's easy for us all to feel that way about them because he and Chrissy just have this warm way of inviting us into their world — the highs and the lows."
She continued, "Our hearts go out to you both in this very difficult time and I'm thankful that you continue to share your light and your talent with all of us for the very special performance, possibly my favorite of the night," Clarkson declared.
Brooks is the only musician to amass eight diamond-certified albums, each with sales at more than 10 million. He remains the top-selling solo artist in U.S. history, with more than 156 million albums sold.
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As a result of the coronavirus pandemic, the 2020 Billboard Music Awards were postponed from the originally scheduled April 29 date. At the time, the ceremony was set to take place in Las Vegas. Tonight's show is broadcasting from the Dolby Theatre in Los Angeles instead.
Last month, BBMA revealed the 2020 list of nominees. The most nominated artist of the night, Post Malone, is up for a total of 16 BBMAs. Just a few nods behind him, Lil Nas X is nominated for 13 awards. Khalid and Billie Eilish are also top contenders, both with 12 potential wins.