A quarter-century after its Broadway debut and after many false starts, "Dreamgirls" the musical finally arrives as "Dreamgirls" the movie. Bill Condon, who penned the screen adaptation and directed the film, squeezes every ounce of entertainment value from the show thanks in large measure to a dream cast that has Jamie Foxx, Beyonce Knowles and Eddie Murphy leading a large, talented ensemble into a flurry of singing, dancing and shouting. Everyone works off one another's energy and talent, giving us many can-you-top-this moments.

If there is a disappointment, it is this: The anticipation may have exceeded the realization. It's a damn good commercial movie, but it is not the film that will revive the musical or win over the world. The best thing about this movie may be our introduction to newcomer Jennifer Hudson. So the boxoffice prognosis for "Dreamgirls" is fuzzy. It should enjoy a successful theatrical run and a decent afterlife in ancillary markets, but perhaps not as much as DreamWorks and Paramount are counting on.

The film moves nimbly through many musical numbers as scenes merge into each other, and the glamour -- period costumes, sets, songs and dances -- escalates as a 1960s female singing group transforms from girls to women with new gowns, wigs and sumptuous digs. But the backbone to the story, the drama of behind-the-scenes relationships and their mutual deterioration, is only a sometimes thing. The characters never quite shake off their easily pigeonholed, overstated stage personas to emerge as full-blown movie characters.

This is, of course, a not even thinly disguised story of Diana Ross and the Supremes. The movie follows the rise of a group of backup singers (the Dreamettes) to stars (the Dreams) under the guidance of their Svengali-like manager, a trajectory that tracks a decade of change in popular music as everyone in the music industry searches for a new sound and look.

The first act or so plays remarkably flat. Predictably, everyone is scurrying to grab the brass ring of showbiz success, so the only real conflict is that of bucking the odds. But we know our Dreamgirls will be winners from the moment the Detroit youngsters are spotted at an amateur talent contest by car salesman Curtis Taylor Jr. (Foxx), who has his own dreams of musical management.

He persuades the girls to sing as backup for rising R&B artist James Early (Murphy). Their lead singer, Effie (Hudson), really needs persuading as her Aretha Franklin-style vocals do not belong as backup. But her "skinny" comrades, Deena Jones (Knowles) and Lorrell Robinson (Anika Noni Rose), are all too eager to climb aboard the tour bus.

When Early bombs before an all-white audience at a Florida hotel, Curtis persuades management to let the girls replace him with their more mellow-sounding act. (How he pulled that off is never explained or explored; it just happens.) The kicker, though, is that he wants shy backup singer Deena to switch roles with Effie. Her sleek look and style is what he wants to sell, not Effie's brass.

Real drama finally flares as Effie grows increasingly angry and morose. Finally, Curtis kicks her out of the group with everyone's blessing, even her songwriter baby brother C.C. (Keith Robinson). As the Dreams rocket to fame, Effie becomes a welfare mother. Why Effie with her huge talent cannot find another job in music is another inexplicable thing that just happens.

As the years roll swiftly by, Curtis strives to produce a sound that homogenizes the soul and R&B in order to appeal to crossover audiences. His black performers, including Deena, who is now his wife, finally rebel. Thus, Curtis becomes the movie's villain. The only problem is, he's been right all along. His sound has produced one chart-topping LP after another and a fabulous house in Los Angeles. Consequently, Deena's dissatisfaction occurs, as it were, overnight, without any build-up to show that maybe she has good ideas, too.

Henry Krieger's music and Tom Eyen's lyrics, with their echoes of Motown, blues and disco, nicely survey an era in pop music trends. What may surprise contemporary movie audiences, though, is the movie's adaptation of the stage show's convention of letting characters burst into song offstage.

The sensation here is Hudson, who delivers a soulful performance, capping it with Effie's showstopper "And I am Telling You I'm Not Going." Meanwhile, Knowles shows more flair than her character is supposed to have. Murphy is terrific on vocals, but his character never comes into focus as he is offstage for extended periods. Foxx has to do the heavy lifting as the villain, and he never settles comfortably into the role.

Virginia Katz's editing and Tobias Schliessler's cinematography keep things moving right along, an adept imitation of the late Michael Bennett's original Broadway staging. At the time, Bennett's work was called "cinematic." Funnily enough, the movie version feels theatrical.