The mission of the Boston Children’s Chorus, whose singers are diverse as Boston itself, is to harness the power of music to promote social justice. In tonight’s Martin Luther King Jr. concert in Jordan Hall, the young men’s choir will undoubtedly shake things up with a work based on the raw utterances of unarmed black men in tragic encounters.

Choir rehearsals move beyond the notes to knocking down barriers of race, religion, gender, and class through conversation about what’s in the news and how it affects the singers’ lives. Choir director Anthony Trecek-King, an African-American who grew up in Nebraska, looks for songs that spark conversation and take the audience on a journey.

When Trecek-King encountered a work called “Seven Last Words of Unarmed Men” by 28-year-old African-American composer Joel Thompson — a reference to the seven last words of Jesus, as recorded in the Bible — he knew he hit a gold mine.

The “Seven Last Words” here are actually not single words but phrases like Eric Garner’s “I can’t breathe," John Crawford’s “it’s not real” and Trayvon Martin’s “what are you following me for?”

The young men sing the words of someone roughly their age. In rehearsal, Trecek-King reminds the boys that 17-year-old Trayvon Martin spoke these words in 2012 to a neighborhood watch volunteer who pursued and fatally shot him. The music is nervous and suspenseful. To deliver the words just right, Trecek-King tells his singers to think about what it feels like to be followed.

“I know I have singers who have experienced that, who have been followed — whether in a store or neighborhood — only because of the color of their skin,” Trecek-King said. “So why not share that with the world? Why not sing about that? Why not give them a place to express themselves in that angsty way?”

But Trecek-King admits to some reservations about performing the work.

“Bringing this up and singing about it, are we going to turn some people off?” he asked rhetorically. He says he once received a response from an audience member who wrote, :I didn’t want to hear this from these kids. I just wanted to hear kids singing joyfully."

“But ultimately,” Trecek-King, said, “I feel it’s something we have to do.”

Amadou Diallo was a 23-year-old African immigrant who in 1999 was shot 41 times by NYC police officers who mistook him for a serial rapist. In a final telephone conversation with his mother, Diallo excitedly told her he was going to college.

Amichee Egbunike, the son of Nigerian immigrants, is one of the soloists in the movement called “Mom, I’m Going to College.”

“When I was singing it, I felt despair and sadness,” Egbunike said. “Who gets to go to college? As a black individual, it’s even harder. That was such an accomplishment, and that was snatched away from him.”

But the singers of every skin tone feel it. They’re high school students applying to college, feeling the excitement of getting in, of their lives going forward. And the conversations about race have sensitized them to harsh realities.

Sebastian Themelis, another soloist in the movement, said the enlightenment at rehearsals is vitally important.

“I live in an environment where it’s so easy not to care about any of these issues,” he explained. “I live in a predominantly white, middle-class neighborhood and go to an all-male private school. It’s so easy to remain blissfully ignorant of racial issues. The discussions we have here I wouldn’t have anywhere else to do it. And [I] wouldn’t meet people affected by those issues.”

A theatrical touch delivers the ultimate emotional wallop. At the start of the Diallo movement, ten of the singers lie in disarray on the floor, as if shot. They sing while lying on their backs. And during a silence just before the end, the four soloists suddenly drop to the floor. The sound of bodies hitting the ground is haunting.

For a full five seconds after a recent performance ended, there was no response other than moist eyes.

“People didn’t know, 'Should I clap?” Should I not clap?'” Trecek-King recalls. “When you’ve got an audience, and they have no idea what to do at the end of the songs? Then you’ve got them.”