Soon after Thanksgiving, Carla Sheffield put up a Christmas tree in her Dorchester home to mark the season, and also to remember her son. Christmas was his favorite holiday.

“He was 26. He was the glue to the family,” said Sheffield.

Burrell Ramsey was killed six years ago, after a traffic stop turned into a deadly confrontation with Boston police. An investigation showed the police officer shot in self-defense, something Sheffield has never accepted.

“I’m angry at the way they treated me,” she said. “I’m angry at the facts they ignored.”

Her anger and pain inspired a poem she wrote called "Hey Officer."

You wear a uniform pretending to be a cop

When he asked you not to

You raised your gun and shot

Now I’m left to wrap this around my head

Boston police just shot my son dead

This holiday season, Sheffield has been performing the poem around Boston, sharing the stage with some unlikely fellow performers: Boston police officers. The have come together as part of Code Listen, an effort to use music to build trust between community members and police.

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Members of Code Listen, an effort to use music to build trust between community members and police, rehearse ahead of a performance. Violinist Shaw Pong Liu launched the project in 2016 when she was named one of Boston’s first artists-in-residence.
Meredith Nierman WGBH News

Violinist Shaw Pong Liu launched Code Listen in 2016 when she was named one of Boston’s first artists-in-residence.

“I had a very naïve idea that, oh we’re going to talk about racism, we’re going to talk about police brutality, we’re going to talk about violence and we’re going to do that all within knowing each other over a few months,” Liu said. “For individuals to talk about that takes time. It takes trust building.”

Along with Sheffield, the group now includes several other mothers who lost sons to violence. Everyone tells their stories — young people, parents and police.

“One of them, I believe it was Gabriel, talks about how he feels discriminated against wearing a police uniform. And when he said that, it made me think,” said Sheffield, “they go through a lot, too. But if we’re bumping heads, how [are] we supposed to fix this?”

The voices of Code Listen reach beyond local audiences. Liu has written a song that incorporates the voices of people she has met through Code Listen, and she performs it at concert halls around the country with Silkroad, an ensemble founded by cellist Yo-Yo Ma.

“I feel really supported in this project over the three years by Yo-Yo and by his encouragement around it,” said Liu. “We have protesters' voices: ‘No justice, no peace,’ ‘Same story every time,’ ‘Being black is not a crime.’ Those words, and those people’s voices in the concert hall is really important for me. And it might not be revolutionary to anyone outside of the arts community, but ... it’s unusual to do that in a concert hall.”

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Violinist Shaw Pong Liu (center left) launched the Code Listen project in 2016.
Meredith Nierman

Code Listen will wrap up its local concerts this year with a pair of performances Saturday, Dec. 15 at the Isabella Stewart Gardner Museum. The concert hall will be filled with dozens of poster-sized photos of victims of street violence, some the sons of the women performing on stage.

“What people who come to the concert will see, it’s mostly young men of color, a few young women, almost nobody white,” said Liu. “And when you look at that ... how does anyone question the fact that we have huge racial inequity in this country and huge problems, if it’s normal that we lose our young people of color, and it’s not normal to lose a white person? How is that acceptable?”

Boston Police Detective and bass player Jeremiah Benton has been with Code Listen since it began. He said his fellow officers have a range of reactions to his side gig.

“Some of them laugh. Some of them say, 'Oh my goodness, I didn’t know you had talent,'” said Benton. “I encourage them to come out and see and listen to what’s going on in hopes that it will spread the message that if we all start to listen to one another we can actually being to hear what one another’s saying.”

It may seem improbable that music could impact what happens on the streets, but as Carla Sheffield pointed out, it can create change. When she first realized Code Listen included police officers, she said she froze.

Two years later her reaction to the police offers who perform by her side is far different.

“I love them,” she said, “I love them.”