OAKLAND — It’s been called the Kaepernick effect, by some media observers.

And the latest silent protest was waged by Oakland Unified School District’s Honor Band at Tuesday night’s Oakland A’s game in the Oakland Coliseum. Many members of the district’s all-star band, which includes both middle and high schoolers, knelt in solidarity with San Francisco 49ers quarterback Colin Kaepernick while playing the national anthem before the game, to protest lingering racial injustice.

Posted on the district’s Facebook page is a photo of the band, with many of its members kneeling, while still playing their cellos, violins, trumpets and trombones.

“Toward the end of the song, most of the 155 middle and high school students took a knee in protest against police brutality and unfair treatment of people of color in America,” the posting reads. “The crowd responded with enthusiastic applause.”

The video was posted on the district’s Instagram page and has since gone viral on social media, said school district spokesman John Sasaki, who captured the video. By early Wednesday morning, the post had been seen more than 425,000 times, shared more than 3,300 times and liked 4,400 times. It’s also drawn media attention from the New York Daily News’ Shaun King, who tweeted it with the caption “BEAUTIFUL.” His tweet has been liked 4,200 times and retweeted 2,500 times.

“OUSD is proud to have such thoughtful and courageous students,” Sasaki said. “They knew that this was a controversial issue across our nation, and yet they decided to go ahead with their protest knowing it would not be well-received by some Americans. They are proud that they have helped to further this important discussion.”

Ever since Kaepernick decided not to stand during “The Star-Spangled Banner” before a preseason NFL game, it’s set off a tidal wave of like-minded protests at sporting events throughout the nation. Among them was a protest in San Mateo, when the San Francisco Mission High School football players gathered together and all but one knelt down rather than stand, according to media reports.

“I am not going to stand up to show pride in a flag for a country that oppresses black people and people of color,” Kaepernick told NFL.com, in response to backlash for his protest. “To me, this is bigger than football, and it would be selfish on my part to look the other way. There are bodies in the street and people getting paid leave and (are) getting away with murder.”

Zack Pitt-Smith, the band director at Edna Brewer Middle School, who helps to lead the honor band, said he didn’t know until the rehearsal before the show that the students were planning to make such a stand. The idea originated with a few students first and then spread.

“It came from a few students. It was not mandated by a teacher,” he said. “And it was a really powerful message from students who are living a reality and really wanting their voices to be heard.”

“The students really expressed a desire to show their solidarity with, not necessarily with Colin Kaepernick, but the movement that is quite evident in their world,” he said. “They wanted to express what they see as racial injustice in their world.”

In fact, students were well aware of the hoopla surrounding Kaepernick’s gesture and what it would mean to stage such a protest, having discussed earlier as a class what their roles as musicians were in playing the national anthem. The class had some really heartfelt discussions about the stories of police brutality that have popped up across the country, he said. They also debated what it means to be supportive of the country and at the same time critical of it.

And “they likened it to being supportive of the troops, but at the same time against the war,” he said. “They are aware of what’s going on, and they want a voice.”