Jennifer Hudson, Beyonce Knowles and Anika Noni Rose

"Dreamgirls" is alive with the sound of music. It's a love song two times over, a tribute to a vibrant period of American popular music as well as to a style of filmmaking we don't get to see enough of, the big budget Hollywood musical.

As directed by Bill Condon, who also wrote the adaptation of the multiple Tony Award-winning play, "Dreamgirls" tells a familiar story with conviction and pizazz. It's a smartly entertaining example of updated traditionalism, of using modern energy and techniques to galvanize a story that was old-fashioned when director Michael Bennett dazzled Broadway with it in 1981.

Based loosely on the career of Diana Ross and the Supremes, "Dreamgirls" is a classic backstage story, a look at the news behind the news of how a humble girl group called the Dreamettes made its way to the pinnacles of musical success and cultural influence. And, get out those handkerchiefs, of the emotional price that had to be paid along the way.

This scenario wasn't exactly profound the first time around, but writer-director Condon so understands the emotional and technical demands of musicals (he was Oscar-nominated for the "Chicago" script) that he makes it feel fresh and alive. Plus he's added more of a context of the social upheaval of the 1960s and he's gotten terrific help, not only from his confident production team but also from the bottom half of his starring quartet.

For though "Dreamgirls" is well-served by charismatic stars Jamie Foxx as pop music Svengali, Curtis Taylor Jr., and Beyonce Knowles as Deena Jones, his beautiful Trilby, much of the film's appeal comes from the surprisingly compelling work of costars Eddie Murphy and Jennifer Hudson, neither of whom were inevitable for their roles.

Murphy, who reportedly had to be talked into the part, gives the most fully rounded performance of his career as James "Thunder" Early, the Thunder Man himself, a soul singer of the James Brown/Jackie Wilson variety who gives the Dreamettes their first big break when he and his manager Marty (Danny Glover) hire them as his backup group.

Using his matchless comic gifts and fox in the henhouse charm, Murphy eats this part alive, making more than anyone else could of this creature of complete self confidence and seduction. And when things become more serious and dramatic for his character in the second half, Murphy -- helped by strong work by Anika Noni Rose as Dreamette Lorrell Robinson -- is ready for that challenge as well.

It wouldn't mean much to say that Dreamette Effie White is the role of Jennifer Hudson's career because this is her film debut following time spent on "American Idol." You'd never know it, though, because under Condon's direction she gives a fearless performance as the Dreamette who pays a price for having a mind of her own. And when she rips into the musical's Tom Eyen/Henry Krieger signature song, "And I Am Telling You I'm Not Going," her singing tears the screen apart.

Though not all the songs in the production, including four new tunes written for the film, are as strong and memorable as this one, "Dreamgirls" is unapologetic about front-and-centering its music. Because it is a story about singers who have to rehearse, perform and record, no opportunity is neglected for the kind of syncopated soul music and showmanship that characterized the Motown sound.

"Dreamgirls" in fact begins in Detroit, with the Dreamettes showing up at a local theater to take part in a talent show. Besides getting a gig touring with the Thunder Man, they also acquire a manager in the form of Mr. Taylor, a Cadillac dealer who has designs on not only entering but changing the music business, on getting "our music to a wider audience with our money."

This is a strong vision, but as it plays out over the course of "Dreamgirls," it is complicated by the fact that Taylor turns out to be the scoundrel of the piece, someone who is willing to play romantic and career games with both Hudson's Effie and Knowles' Deena if it helps to get that dream realized.

Just as "Dreamgirls" needs someone of Knowles' allure and skill to make Deena creditable, it also needs Foxx' ability to project magnetism even when he is being pulled back and withholding. The film also couldn't exist without the zesty contributions of those responsible for its look: cinematographer Tobias Schliessler, production designer John Myhre, editor Virginia Katz, costume designer Sharen Davis, choreographer Fatima Robinson, and so on down the line. "Dreamgirls" is the entire musical package, a triumph of old school on screen glamour, and we wouldn't want it any other way.