Long before Barack Obama and Rahm Emanuel teamed up, another black-Jewish duo rumbled out of the South Side of Chicago to change the world.

Leonard Chess, the son of a Polish immigrant and a seat-of-the-pants entrepreneur, and McKinley Morganfield, a Mississippi sharecropper and guitar player reborn as Muddy Waters after he came north, forged a profitable and influential partnership in the late ’40s and early ’50s.

Their symbiotic relationship provides the through line for Darnell Martin’s colorfully episodic yet disappointingly routine “Cadillac Records.” In typical Hollywood fashion, the movie oversimplifies, airbrushes and shrinks a gritty chunk of cultural and social history into a bite-sized nugget of nostalgia.

Curiously, “Cadillac Records,” which opens Friday, Dec. 5 in the Bay Area, bypasses the opportunity to explore the largely forgotten relationship between Jews and blacks in the North after the war. The movie is simply another riff on the rags-to-riches rock ‘n’ roll story, accessorized with a dash of racial content.

The young Chess runs a junkyard as the film opens, not an enterprise likely to impress a father who wants his daughter to marry an upwardly mobile Jew in postwar America. Chess (Adrien Brody, who mysteriously never ages as the movie goes along) shakes off this romantic setback and moves on to his next venture, a nightclub with live music. From that point on, he is identified not as Jewish, but as white.

The club is where he meets Muddy Waters (Jeffrey Wright), a brilliant guitarist with a fresh sound immeasurably enhanced by the urgent backing of harmonica prodigy Little Walter (Columbus Short). Chess pulls the combo into a recording studio, and soon realizes he’s in the wrong business.

So he starts a record label and recording studio under the banner Chess Records with the insurance settlement after the club burns down. That little detail is presented here as one of numerous illegal and quasi-illegal practices, such as paying DJs to play his records, that the opportunistic boss man employs to build and sustain his company.

While Chess knows how to make money, Waters is singularly adept at spending it. The first rock star, essentially, Waters basks in the fame, wine and women (even though he’s married). He’s a bluesman turned showman, an artist seduced by the trappings of success, as the arrival of the no-nonsense Howlin’ Wolf (a hulking, intimidating Eamonn Walker) underscores.

Of course, Chess is living the high life as well, with a big home and a new Cadillac. His vices aren’t women or liquor, but money and the ego kick of discovering new hit makers, such as Chuck Berry.

The touchy subject of a Jewish businessman exploiting unsophisticated black musicians is crudely broached a dozen times, but there’s too much affection between Chess and Waters and too much self-destruction on the part of Little Walter and subsequently Etta James (Beyoncé Knowles), for the charges to stick.

Chess is presented as a man who pocketed royalties with one hand and paid out with the other whenever an artist needed help. The movie wants us to see him as a conflicted, complex character whose priority was his company yet genuinely cared about his musicians, but the picture is blurry and unfocused.

Likewise, the preponderance of vintage pastel Cadillacs doesn’t have the effect the filmmaker intended. We don’t see them as symbols of success and conspicuous consumption, which Chess adores and happily bequeaths to his artists when they score their first big sellers, but as alluring Americana.

Perhaps the most damning contradiction is that the movie focuses more on the rockin’ melodies of Chuck Berry and the smooth ballads of Etta James, while in reality, Chess Records was founded on the raw nastiness of electric blues.

The risk of pursuing crossover success, as “Cadillac Records” unintentionally illustrates, is losing one’s essence.

“Cadillac Records” opens Friday, Dec. 5 in Bay Area theaters.

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Michael Fox is a longtime film journalist and critic, and a member of the San Francisco Bay Area Film Critics Circle. He teaches documentary classes at the Osher Lifelong Learning Institute programs at U.C. Berkeley and S.F. State. In 2015, the San Francisco Film Society added Fox to Essential SF, its ongoing compendium of the Bay Area film community's most vital figures and institutions.