Pharrell Williams headlined the Concert for Charlottesville on Sunday night and joined in protests of Donald Trump’s recent comments about NFL players kneeling during the national anthem. The concert, an event hosted by Dave Matthews following the deadly protests that took place in the Virginia college town last month, gave Williams the platform he needed to speak out against Trump.

“I wanna get on my knees right now,” Williams said.

“If I want to get on my knees right now for the people of my city, for the people of my state, that’s what that flag is for,” Williams said regarding the anthem and the American flag.

Over the weekend, various celebrities stood in solidarity with Colin Kaepernick and other NFL players who have taken a knee during the national anthem to protest police brutality and injustice against people of color.

Stevie Wonder took a knee during the Global Citizen Festival: “Tonight, I’m taking a knee for America, but not just one knee—I’m taking both knees. Both knees in prayer for our planet, our future, our leaders of the world and our globe. Amen.”

And John Legend wrote an op-ed for Slate on the true meaning of patriotism and protests: “Protest is patriotic. Protest has played a critically important role in elevating the voices of the most vulnerable in our nation. ... They are the definition of patriotism. ... Every time someone takes a knee or raises a fist, viewers must grapple with the why—with the uncomfortable reality that our country daily marginalizes thousands of people in impoverished communities.”