In the accompanying statement, he challenges fellow musicians and Americans to shine a light on racism in their own way using the hashtag #TakeTwoKnees — which he says is a tribute to Colin Kaepernick's kneeling protests of police violence.

From his home in Riverdale, the Bronx, McGill spoke to NPR about creating the post, the responses it has inspired (including videos by the Met's principal trumpeter Billy Hunter and opera tenor Lawrence Brownlee), and why he believes even small gestures of protest can have a real effect.

It's demonstrated by the reaction people have, which is initially what was very shocking to me about Black Lives Matter — that lots of people immediately struck that down, as though people weren't allowed to say something that should be taken as a fact.

Many people have been quoting a passage from one of Martin Luther King Jr.'s speeches: "As long as America postpones justice, we stand in the position of having these recurrences of riots and violence over and over again.

It was really moving to me when Billy Hunter, the trumpeter for the for the Met orchestra, responded to your post by playing part of "The Star-Spangled Banner" and leaving out the notes for some of the key final words.