The singer and producer Pharrell Williams is the latest entertainer to show solidarity with N.F.L. players protesting President Trump’s call to fire players who refuse to stand during the national anthem.

At a charity show on Sunday in Charlottesville, Va., where violent demonstrations took place in August, Mr. Williams said, “I’m in Virginia right now, I’m home. Can’t nobody tell me what to do if I want to get on my knees right now.” He then dropped onto both knees.

Mr. Williams’s display follows a wave of demonstrations across the country on Sunday as N.F.L. players knelt or locked arms during the national anthem in defiance of Mr. Trump. The “Take a Knee” protest has now grown beyond the sporting world, and entertainers and performers are joining in.