The newest Lincoln Center musical, “Dessa Rose,” performs a neat trick. Writer Lynn Ahrens and composer Stephen Flaherty set out to tell a story about a brutalized, pregnant slave, but they never once horrify their audience, or startle it, or even make it vaguely uncomfortable. They have pulled a surprisingly cuddly rabbit out of a very dark, very dangerous hat, turning a journey through hellfire into a cheerful march to female solidarity. “Slavery didn’t do away with love or heroism. It provided occasions for both,” they tell us.

Adapting the novel by Sherley Anne Williams, the same team that brought us “Ragtime” try to keep as much of the book intact as they can. In so doing, they give us a barrage of narrators, a dozen framing devices, and a wandering, undramatic second-act. What they miss is Ms. Williams’s specificity – the sensation that a “summer in the 1800s” had been brought alive to haunt us again.

Dessa Rose (LaChanze), pregnant, guilty of attacking her master and inciting a slave revolt, molders in jail, awaiting death. Elsewhere, lily-white Ruth (Rachel York) languishes on her plantation, raising an infant, abandoned by her husband, and struggling to command the slaves he has left behind. Dessa’s escape from her pit, aided unwittingly by white biographer Adam Nehemiah (Michael Hayden), lands her at Ruth’s door. Horribly scarred from the whip, nearly dead from exhaustion, and in labor, she can hardly fend off Ruth’s help, even when the white farmer’s wife takes Dessa’s baby to her own breast.

At first, Dessa Rose and Ruth are at daggers drawn, especially when Dessa discovers Ruth in the arms of one of her fellow escaped slaves. But poverty and necessity drive them together. Ruth’s lover Nathan (Norm Lewis) hatches a plan – Ruth, irreproachably white and genteel, “sells” the others, then splits the proceeds with them once they escape. Adam Nehemiah, though, pursues Dessa Rose from county to county, driven nearly mad by the twin goads of vengeance and sexual obsession.

Ms. Williams’s story subverts the usual conventions, letting a female friendship stand center stage while romantic entanglements must make do with the margins. Ms. Ahrens and Mr. Flaherty describe as many strong women as they can, from a “Mammy” Ruth realizes she never understood to the stately Auntie Chole who bails Dessa out of a bad spot.

But strong women deserve magnificent music, and Mr. Flaherty doesn’t provide it. When we catch a glimpse of the real hymn “I’ll Fly Away,” buried under a saccharine orchestration, we notice the absence of real spirituals and hymns. Same sounding, generic “uplift” doesn’t substitute for the kind of music that kept a people alive.

Director Graciela Daniele has a nasty task laid out for her – should she graphically represent the violence of slavery, something that would always fall short of the real event, or should she stylize and abridge where she can? Ms. Daniele goes with her more theatrical option – Dessa wears no shackles, a scene of murderous rage turns into a scuffle accompanied by thumping farm implements. None of her gambles pay off emotionally.

To be fair, the music at her disposal doesn’t adequately convey pain or resilience. And she is hobbled by her material. The worst convention, with Dessa and Ruth switching in and out of their “old” personalities when they narrate, leaves otherwise strong actresses stranded. The play, though, demands it. Never mind that having the old women tell the story in retrospect robs the story of its suspense and danger – it’s just embarrassing to see LaChanze have to go all toothless and stooped in midsentence.

There are few forms more instantly divisive than the musical. The way rhyme can set an audience up, making it anticipate an important word, can be deadly or delicious depending on the ear. And taste alone determines if a song about breast-feeding will irritate or entertain, or if a manipulative key change will set your teeth on edge.

Until May 29 (Lincoln Center, 212-239-6200).