Brilliantly cast and ambitious to beat the band, "Cadillac Records" is a little movie that aims big. It tries to capture nothing less than the moment when white culture embraced black music and rock 'n' roll was born.

But even if the iPod Nation craves this history, the movie overreaches in trying to capture all that Chess Records witnessed.

It's the label that summoned delta blues to Chicago and electrified it, where Muddy Waters growled and Howlin' Wolf howled, where Chuck Berry invented rock guitar and where Etta James sang the greatest make-out music ever recorded.

This film by veteran TV director Darnell Martin ("Their Eyes Were Watching God") hits many of the highs and lows of this storied history. She brings in integration, radio payola scandals and the Chess influence on those who came later (the Rolling Stones).

It's edgy enough to have blues men and women talk the way blues men talk and indulge in their indulgences. But it's a dry and somewhat whitewashed look at a place where musicians made money and history, mostly the latter.

Oscar winner Adrien Brody plays Leonard Chess, the striving immigrant who traded in his junk business for a juke joint and then burned that down to finance the birth of Chess Records. This Chess is a father-figure crook, treating musicians like "family," paying them off in fancy automobiles and never letting them look at his books.

"Welcome to Cadillac Records," his first artist, Muddy Waters (the superb Jeffrey Wright) tells Howlin' Wolf (Eamonn Walker). "You stay around long enough, everybody gets one," meaning a Caddy.

Chess songwriter Willie Dixon (Cedric the Entertainer) traces Waters' career from his discovery as a blues-playing sharecropper to his decades of Chess servitude, the good woman (Gabrielle Union, well cast) he cheated on, the harmonica-playing rival, Little Walter (Columbus Short) who lived hard and suffered for it. Mos Def is a dead-on Chuck Berry, mastering the master's musical playfulness and personal bitterness and mistrust. Beyoncé Knowles is beyonc-ilicious as Etta James, a deeply troubled singer who was the very essence of "soul."

Writer-director Martin has made a competent but misshapen movie.

Her cluttered script robs the film of the heart of a "Ray" or "Walk the Line." It's so much that it's no wonder that she mucks up the chronology. Martin even edited out Phil Chess, the other half of the "Chess brothers" who founded the label.

Knowles and Brody heat it up, but while most of the characters age, Brody's doesn't. Or get a haircut.

Any student of early rock history would have to be concerned that Hollywood might have only one chance to get this right. "Cadillac Records" doesn't manage that, but with this cast doing its own singing, and history this rich, it's close enough for rock 'n' roll.