WASHINGTON — Performers such as Gladys Knight or the Irish band U2 usually would be headlining a concert for thousands, but at Sunday's Kennedy Center Honors the tables were turned as they and other artists were feted for their lifetime of artistic contributions.

Actor, director, producer and human rights activist George Clooney, groundbreaking composer and conductor Tania León, and contemporary Christian singer Amy Grant will join Knight and the entire crew of U2 in being honored by the John F. Kennedy Center for the Performing Arts.

The organization honors a select group of people every year for their artistic influences on American culture. President Joe Biden, Vice President Kamala Harris and their respective spouses were in attendance.

Biden paid tribute to the honorees before the ceremony at the White House Sunday afternoon, praising them before a star-studded East Room crowd as an “exceptional group of artists.”

“Thank you for showing us the power of the arts and ‘We the People,’” Biden said.

He highlighted Clooney’s on-camera work and off-screen charity endeavors, from helping 9/11 victims’ families to supporting a gun control campaign led by the survivors of the Parkland school shooting.

“He is unrelenting and undaunted,” Biden said. “That is character in real life. And that is George Clooney.”

Biden hailed Grant’s voice as “a true gift from God that she shares with everyone,” thanked León for ’breathing new sounds into the soul of the nation,” and said he has all of Knight’s songs on his iPhone.

“We’re going to get on that midnight train,” Biden said of Knight. “Because I speak for all Americans when I say we we’d rather live in your world than be without you in ours.”

Biden, noting his love of Irish poets, called U2 “four sons of Ireland, poets in their own right” whose music “has changed the world.”

“We would do well to remember today at a moment when there’s too much hate, too much anger, too much division here in America, and quite frankly, around the world,” Biden said. “We have to remember today, as their song goes: ‘We are one but we’re not the same. We get to carry each other.’”

On the red carpet ahead of the Kennedy Center show, Clooney, with his wife, Amal, beside him, joked that after seeing friends like Don Cheadle and Julie Roberts in attendance he was worried his tribute would be more of a “roast.”

Growing up in a small Kentucky town, he said, he watched the Kennedy Center Honors on TV adding that he was excited to be part of a fraternity that includes actors such as Paul Newman and Henry Fonda.

During the ceremony, an emotional Patti LaBelle called Knight her “everything,” saying they had been friends for six decades and seen each other through laughter and tears. “We do everything together,” LaBelle said. “I am honored to honor you tonight.”

Country music superstar Garth Brooks, citing Knight's "roots in country music,” sang her classic “Midnight Train to Georgia.”

U2 has sold 170 million albums and been honored with 22 Grammys. The band’s epic singles include “I Still Haven’t Found What I’m Looking For,” “Pride (In the Name of Love)” and “Sunday Bloody Sunday.” Lead singer Bono has also become known for his philanthropic work to eradicate poverty and to raise awareness about AIDS.

Grant is well known for crossover pop hits like “Baby, Baby,” “Every Heartbeat” and “That’s What Love is For.” She’s sold more than 30 million albums, including her 1991 record “Heart in Motion,” which introduced her to a larger pop audience.

León said during an interview when the honorees were announced that she wasn't expecting “anything spectacular” when the Kennedy Center initially reached out to her. After all, she's worked with the Kennedy Center numerous times over the years going back to 1980, when she was commissioned to compose music for a play.

But the 79-year-old Pulitzer Prize winner said she was stunned to learn that this time the ceremony was going to be for her.

León left Cuba as a refugee in 1967 and eventually settled in New York City. She's a founding member of the Dance Theatre of Harlem and instituted the Brooklyn Philharmonic Community Concert Series. (AP)