Demi Lovato, Amy Schumer and Clooneys among celeb support at March for Our Lives

Amal and George Clooney, Amy Schumer and Kanye West were among the high-profile figures who joined the March for Our Lives rallies Saturday led by students calling for gun control.

'What's in it for us is knowing we're doing our part to keep our children alive,' says Schumer

Singer Demi Lovato performs at the rally in D.C. (Nicholas Kamm/AFP/Getty Images)

Galvanized by a shooting massacre at a Florida high school, hundreds of thousands teenagers and their supporters — including a number of celebrities — rallied in Washington, D.C., and other cities across North America to push U.S. politicians for gun control safety laws.

Common and Andra Day performed their Oscar-nominated song Stand Up For Something from the 2017 film Marshall. Day kicked off the D.C. rally with her anthem Rise Up.

Common and Andra Day performs Stand Up For Something. (Chip Somodevilla/Getty Images)

Hamilton creator Lin-Manuel Miranda and Dear Evan Hansen star Ben Platt performed Found/Tonight, a mashup of songs from their hit Broadway musicals. Miranda told demonstrators: "Don't give up."

Miley Cyrus, Demi Lovato and Ariana Grande, whose Manchester concert venue was the site of a terrorist bombing last year in Britain, also performed in the U.S. capital.

Lin-Manuel Miranda, at left, and Ben Platt, at right, perform Found/Tonight, a moving rendition of ballads from both their hit Broadway musicals. (Chip Somodevilla/Getty Images)

Jennifer Hudson, who wrapped Saturday's event with a performance of The Times They Are A Changin,' alluded to the shooting deaths of her mother, brother and seven-year-old nephew in 2008.

Human rights lawyer Amal Clooney and husband George Clooney also joined the D.C. rally, as did Kanye West, wife Kim Kardashian West and daughter, North.

In Los Angeles, Trainwreck actress Amy Schumer addressed the crowd, thanking "students and everyone here for standing up and saying 'no more.'"

"What's in it for us is knowing we're doing our part to keep our children alive," she said.

She added there is often a professional cost to taking a political stand.

"It narrows the people who will support our work. We sell half as many tickets because we're standing up for what's right," said Schumer. "And you see that politicians? You can make a little less money and be able to look at yourself in the mirror with no blood on your hands."

Actress Amy Schumer addresses the crowd as they protest for tighter gun laws during the student organized March For Our Lives rally in Los Angeles Sunday. (Mark Ralston/AFP/Getty Images)

Singer Paul McCartney was spotted in New York City, and told CNN: "One of my best friends was killed in gun violence right around here." Fellow Beatles member John Lennon was shot to death in Manhattan in 1980.

Paul McCartney takes part rally held near Central Park West in New York Saturday. (Eduardo Munoz Alvarez/AFP/Getty Images)

Other famous faces lending their support to the gun control movement included Julianne Moore, Steven Spielberg, Kate Capshaw, Glenn Close, Jimmy Fallon and Cher.

With files from the Associated Press