Harris, an acclaimed jazz vocalist, originally conceived the work as a solo song cycle, and has only recently adapted it into a stage vehicle. But it still feels very much like an oil-and-water effort, with over a dozen impressive songs, an informative book about how Blue (Harris) escaped slavery on a Louisiana plantation in the 1850s to become a Texas cowboy, and hardly any sense that the two elements go together.

Blue narrates his own journey from servitude to freedom, introducing us to a wide variety of Southern and Western types: the plantation manager (Timothy Warmen), who's actually a "high yellow" (a light-skinned black passing as a white); the plantation owner's daughter (Whitney Bashor), Miss Courtney, who can't acknowledge her true feelings for Blue; the country preacher (Tony Perry), who's a bigger celebrity than Jesus; the Buffalo Soldiers, troops of distinguished black Civil War veterans; the saloonkeeper, Diamond Jimmy (Joseph Melendez), who also owns three young women, including the black Annie (Wendy Lynette Fox) that Blue takes a shining to.

Everyone gets a song, of course. Blue and Miss Courtney sing a lovely we-can't-acknowledge-what-we-feel waltz in "Another Time, Another Place"; "Dat Dere Preacher" is a jaunty rave-up that bucks most of the usual gospel clichés; one of Blue's professional models, Mule Skinner (Charles E. Wallace), gets a literally whip-cracking song of the same title that plumbs the dark depths of his love for his absent wife; Diamond Jimmy sings of his love for Annie and the secret that could ruin his already-questionable reputation.

Harris understandably saves some of the choicest numbers for himself: "Cross That River," sung with his surrogate mother and fellow slave, Mama Lila (Soara-Joye Ross), as he prepares his escape from the plantation in the wake of his father's death; "Blue Was Angry," in which he and his younger self (Brandon Gill) confront their rage at the start of the journey; the haunting "Cry of the Thunderbird," the only music on the endless, loveless prairie; and a power-packed one-two punch at the end of the second act, "My Dreams Are You" and "I Do Believe," for Blue to meditate on the resolution of his two greatest love affairs: with Annie and with America itself.

Yet Cross That River always feels more like a television documentary than a musical (not surprising given that Wilk, who also directed, has won four Emmys for his TV work), always telling its story for reasons of educational enlightenment rather than emotional absolution. The songs give their subjects only momentary importance, and at the end all the actors step forward to explain how everything ended and what its historical significance was. But theatre pieces relate history best by making the audience part of the unfolding events rather than merely a witness to them - they want to see why things are important, not just hear that they were. Harris and Wilk's this-happened-and-then-this-happened way of storytelling gives their show the feeling of a live entertainment being presented for $20 admission at a Southern history museum.

That's the ideal type of venue for this show - and it's of high enough quality to prove an unbeatable value for any patron dying for a lecture on the 19th-century West - but such a production would probably not have musical staging by Donna McKechnie. As it is, this one barely does - there are almost no real dance numbers, and anyone longing to see exactly what she learned from Michael Bennett won't get much of an inkling of it here. Harris also likely wouldn't want to stick with the show through a sit-down run so far outside of New York, but he's smoothly ingratiating as Blue, handy with a guitar and handsomely affecting the voice of a country crooner. But then, all the people here are good - real period lookers and characterful singers that make you wish they had something dramatic to wrap their talents around.

Only Ross does, and boy, does she make the most of it. With the first-act finale, "I Must Believe," she whips herself and the audience into an ecstatic frenzy as Mama Lila reflects on the liberty she hopes awaits her with her ultimate master, God. Ross blasts into the very depths of her heart and soul to make this not merely a powerful statement against slavery and in favor of faith and freedom, but also so explosively theatrical that comparing it to Jennifer Holliday's "And I Am Telling You I Am Not Going" in Dreamgirls and Fantasia Barrino's "I'm Here" in The Color Purple would not be out of place. Ross draws tears from your eyes and elevates you out of your seat as convinces you there really is a better place for everyone.

It would be a perfect moment if not for one thing: The song is sung for no reason. Mama Lila has long since disappeared from the story, and Harris ushers her back just to stop the show, after which she disappears again forever. Ideally, the song would be Annie's, to better anchor her as the vital female role in Blue's story. As it is, she gets only a minor solo which is unthinkably placed in the first spot after "I Must Believe," when people's bodies are still ringing with the preceding number's catharsis. "I Must Believe" is an amazing song, Ross's performance of it is unforgettable, and Cross That River is a meaningful (if currently misaligned) work, but right now they don't all go together. They will, however, if Harris and Wilk devote more time to the three, and only three, things: location, location, location.

Cross That River
Tickets online and current Performance Schedule: The New York Musical Theatre Festival