If my movie reviews had headlines, this one’s would be: “A Star is Born.” More like a Supernova. Jennifer Hudson explodes onto screen in this incendiary production of the Broadway musical inspired by Motown and the Supremes. She is mesmerizing. She is dazzling. She is fierce. She shimmers. She melts. She breaks your heart and then she puts it back together so she can melt it. Her voice is sensational, but the real surprise is her acting, which is at the same time commanding and vulnerable. She is a star.

The other star of the movie is screenwriter/director Bill Condon, who blasts through the weaknesses in the underlying material (uneven quality of music that is second-rate Broadway and thus tenth-rate R&B, under-written characters, creaky plot) with unhesitating nerve and electric energy. His direction is a kind of choreography all its own, dynamic and organic. In other words, it has a good beat and you can dance to it.

“Dreamgirls” is the story of three young women who have sung together since they were children. Effie (Hudson) sings lead. She has a strong voice, strong opinions and a very strong personality. Effie, Deena (Beyonce Knowles), and Lorrell (Anika Noni Rose) dream of making it as professionals.

They are asked to sing back-up for James “Thunder” Early (Eddie Murphy, in a career-restoring performance). At first reluctant, because they want to be a group on their own, they agree — chaperone included — and we launch into a road montage as they learn about show business, from cramped tour buses to predatory men. Lorrell succumbs to the married Early. Ambitious manager Curtis Taylor Jr. (Jamie Foxx) becomes romantically involved with Effie, but then, when there’s a chance for mainstream success, he replaces her as lead singer and love interest with slender, conventionally pretty, pliant Deena and renames them the Dreams. Soon, Effie is out of the group all together, though on her way out she gets to sing one of the greatest show-stopping songs in the history of Broadway: “And I Am Telling You I’m Not Going,” a gospel-infused powerhouse wail of the heartbreak and rage of rejection.

Taylor builds a recording empire and we get another montage of success and superstardom with a dazzling run of costumes and hairstyles and some soapy sturm und drang until we get to the “had I but known” and “I have to do what is right for me” moments and the big finish.

Along the way, the movie takes on some ambitious themes, from the mainstreaming of R&B into pop to the compromises people make in the name of ambition and the consequences for friends and families. And it is impossible to forget the resonance with the real-life back-stories of its cast — Hudson’s comeback from her loss on “American Idol,” the rumors about Knowles’ own Diana Ross-style diva behavior in the replacement of singers in Destiny’s Child and its subsequent break-up, Murphy’s tabloid appearances and professional slide from Beverly Hills Cop and 48 Hours to Daddy Day Care and Nutty Professor II: The Klumps.

This substance anchors the glossy material, helping it transcend the “Is that supposed to be Barry Gordy? Is that supposed to be James Brown?” questions and making it archetypal instead of derivative, a movie instead of a music video, powerful as well as entertaining.

Parents should know that this film has some mature themes, including racism, behavior that would be deemed sexual harassment, and drug abuse, including an offscreen drug overdose. Characters use some strong language, drink, and smoke. A character has an out-of-wedlock child. A strength of the movie is its frank portrayal of the racism of the era and the way white performers (or less provocative black performers) appropriated the music of minorities who could not get a chance in mainstream outlets.

Families who see this movie should talk about which of the characters made compromises and what the results were. They should also talk about the early days of pop music, when white artists like Pat Boone had hits covering songs from “race records.” Is there still a racial divide in the music business today? How can you tell? Who changed for the better in this story and who changed for the worse? Why?

Families who enjoy this movie will also enjoy Lady Sings the Blues (very mature material), with the Supremes’ Diana Ross as Billie Holliday, Ray, with Jamie Foxx in his Oscar-winning performance as Ray Charles, and other movies about the early days of the rock and R&B music industry Sparkle, American Hot Wax, and Grace of My Heart. They will also enjoy the spectacular documentaries Standing in the Shadows of Motown, Only the Strong Survive, and Lightning in a Bottle.