When the composer Tamar-kali goes fishing in the South Carolina low country, she thinks about her ancestors — the Gullah Geechee — singing spirituals like “Wade in the Water.” And she pictures Harriet Tubman arriving with Union gunboats in the summer of 1863 when those ancestors actually had to wade in the water to their freedom.

The Gullah Geechee, who called Tubman Black Moses, helped create a rich book of spirituals that fused biblical imagery with their own plight. “You think about a people who have been engaging in this faith as a form of coping with their lot in life,” Tamar-kali said, “which is the absolute removal of their agency, their humanity, as chattel slaves.”

Tamar-kali, who lives in Brooklyn, is always thinking about history, and it infuses her Music. The largest expression yet is her “Sea Island Symphony: Red Rice, Cotton and Indigo,” a new work for orchestra and vocalists that is to have its world premiere on Wednesday in Manhattan as part of Lincoln Center’s Summer for the City.

The programmatic symphony paints the Gullah Geechee story from the Civil War through the rise of Robert Smalls, a Carolina man who was born enslaved and became a United States congressman in 1875.

“I’m a full-concept girl,” said Tamar-kali, who began working on the piece in 2019. “I started it and then I realized: Oh, this is not something small. Because it’s like I really go with the guidance from the muses.”

The symphony’s world premiere, performed by American Composers Orchestra, is the culmination of a series she curated called “Freedom Is a Constant Struggle” that has included panel discussions about the complex and often neglected history of America’s Black composers and Classical Music. Tamar-kali said it was important to her that the piece be contextualized and that the series happen around Independence Day to emphasize that “the end of colonial British rule only symbolized independence for a very small population.”

The four-movement “Sea Island Symphony” is the most ambitious addition yet to a composing and performing career that has included punk rock, film scores and opera. Tamar-kali’s eclectic output is the product of wildly varied input — her family’s juke joint in the Sea Islands, blues and jazz, and the Ashkenazi cantorial melodies and classical music she absorbed growing up in New York City.

Tamar-kali describes herself as “a kid that classical music lost.” She received a formal music education at an all-girls Catholic school in Brooklyn in the 1980s, studying theory and singing in a classical choir. But her experience there — she called it “a post-colonial missionary mind-set institutional space” — gave her “no desire to continue that journey that basically felt, to me, like a war,” she said. “So I figured out early on that I would deal with music on my own terms.”

She arrived on the New York musical scene screaming — shredding an electric guitar and belting out lyrics of resistance by way of punk rock, becoming a fixture at Joe’s Pub. Shanta Thake, the new chief artistic officer at Lincoln Center, was an early fan. “If you were just to describe her visually, walking around, she is so fierce,” Thake said. “There’s this warrior fierceness to who she is onstage, and just such a command of the audience, of the songs themselves.”

Another fan from the Joe’s Pub days was the composer Daniel Bernard Roumain, now a professor at Arizona State University. Roumain was living in Harlem in the early 2000s, and he invited Tamar-kali to his apartment, where they recorded a raw electric version of Kate Bush’s “Running Up That Hill.”

“She was this seminal New York artist who was bold and brash, avant-garde,” Roumain said, “incredibly powerful and incredibly inventive. She was a destination, and her career was, even at that time, landmark.”

Tamar-kali transcended punk to found the Psychochamber Ensemble, an all-female string and choral group that also covered Kate Bush. She was dipping back into classical music, and she realized, if only after the fact, that she was trying to recreate the fellowship she had experienced in school choir — but now in a safe space while maintaining her agency. “I didn’t even realize I was trying to heal myself,” she said.

Before long, Tamar-kali’s string writing and story sense attracted film directors. She made her scoring debut with Dee Rees’s “Mudbound” in 2017. She recently scored a PBS documentary about the Gullah Geechee, “After Sherman,” and is working on John Ridley’s biopic of Shirley Chisholm starring Regina King.

The film work is acoustic and often chamber sized, with a handmade quality, created in her studio in the Dumbo neighborhood of Brooklyn. She often incorporates her own singing voice. Her music is always, in a way, vocal, Roumain said: It “is always boundless, is always wanting to speak. In some ways, it can’t be contained.”

She composes most of her music with her voice, which she then translates into software and synth mock-ups before it’s interpreted by other musicians.

It was Roumain who nominated Tamar-kali in 2019 for an Arizona State commission that became the seed for “Sea Island Symphony,” a work she describes, stylistically, as Americana, a synthesis of all of her influences. “It just … it sounds like me,” she said.

The finished symphony opens with a movement depicting the Port Royal Experiment of 1861, in which the Gullah were left to manage themselves in the low country’s undesirable marshlands, with text sung by a tenor representing a newly freed person.

The second movement travels forward to the Combahee River Raid of 1863, when Tubman led a Union military operation to rescue more than 700 enslaved people, and reclaims the true origins of the song “Kum ba yah.” “It’s not about making amends or being all happy and sweet,” Tamar-kali said. “It’s a cry for intercession by the higher power: ‘Come by here, my lord.’”

The segment culminates in a ring shout, a call-and-response circle that enslaved Africans developed to preserve their heritage while strategically not offending their white captors. The singers will be accompanied by a “shout stick,” historically often a mop or broomstick, since drums were outlawed at the time.

The third movement is a scenic piece inspired by General Sherman’s Special Field Order No. 15, an 1865 military order that granted the area’s newly freed people ownership of the Gullah Geechee corridor. Though Tamar-kali’s mother grew up in Beaufort County, S.C., neither mother or daughter knew about this brief idyll when their ancestors owned land — land that was soon repossessed.

The final movement traces the story of Robert Smalls, who used his navigational skills to sail to freedom; he joined the Union army and later become a congressman. Though Smalls’s name is all over his hometown, Beaufort, it’s another piece of history that Tamar-kali discovered only as an adult.

Tamar-kali said she hoped eventually to take the symphony down to the low country and to Washington, D.C. She insisted on this premiere being part of free summer programming, which means it’s one night only, with a small budget and very limited rehearsal.

Having grown up attending free concerts in Brooklyn and Central Park, she knows that “the most multicultural, multigenerational audiences, of the most diverse socioeconomic backgrounds, exist at free public programming,” she said, adding it was “the gateway to diversity in the halls. But it’s overlooked, and it’s underfunded.”

Classical music lost her once. She wants it to find more people like her.