"SHOUT UP A MORNING," at the Kennedy Center Eisenhower Theater, is a pleasant, populist musical about that fabled steel-drivin' man John Henry. But one somehow expects something more muscular and momentous in a musical about the legendary black man who stood up to a mountain, a machine and the white masters.

Developed at California's La Jolla Playhouse, with a score by jazz greats Nat and Julian (Cannonball) Adderley, "Shout" is an attempt to expand the John Henry tale and create a black American parallel to the story of Moses. But even tricked out as it is with high-tech trappings and religious images, this predictable, sentimental "Shout" never really raises its voice.

On a West Virginia mountainside in 1868, a nomadic band of black families trying to earn their fare to the Promised Land are employed by the C&O Railroad to bore a mile-and-a-half tunnel through Big Bend Mountain. Enter John Henry, who announces himself, with no apparent irony, as God's right hand man.

John Henry, who can make mountains quake with a word, charms the tribe and stands down the white bosses. After a crisis of faith, he redeems himself by betting the railroad brass that he can hammer steel faster and farther than the new steam drill that has put him and his fellows out of work.

The book, by Paul Avila Mayer and George W. George, has a choppy cut-and-paste feel. The Adderleys' score is an eclectic mix of ersatz jazz, black spirituals and soul-flavored pop, performed by the house orchestra with competence but little fire. Diane Charlotte Lampert's lyrics are of the vague and generally inspirational nature of top 40 ballads.

The show's most rousing number is a reworking of the traditional "Ballad of John Henry," which accompanies the climactic race between man and machine. Given the power of this theme, it seems odd that so little is made of it. Instead, the creators belabor the romantic subplot.

Director Des McAnuff's staging is conventional and mainly strategic, consisting mostly of grouping and regrouping clumps of people all over John Arnone's towering stage set, which features several mobile walls of stone, a steam locomotive and a grid of spindly red scaffolding, catwalks, ladders and elevators.

Michael Edward-Stevens makes a properly strapping John Henry and swings a mean sledgehammer, but he is not nearly commanding enough to carry the superhuman role. As Carolina, John Henry's beloved, Leilani Jones is given a wisp of a character but makes the most of creamy ballads like "Gonna Give Lovin' a Try," in which she comes across as a 19th-century Whitney Houston.

The ensemble singing is strong and stirring, and several supporting players have standout moments, including Stuart K. Robinson as the shambling scout Jassawa, who evokes chills with a monologue about his mother's harsh lesson in what to expect from life as a black man.

SHOUT UP A MORNING -- At the Kennedy Center Eisenhower Theater through August 9.