The more I get to know Beyonce Knowles through her work, the more impressed I become. There has never been any doubt about her natural talent as a chanteuse, but, frankly, there are a lot of talented singers. What I find increasingly impressive is her business savvy and passion for music and its history.

“Cadillac Records,” in which she serves as both star and executive producer, highlights an often overlooked but crucial period of American music: the blues and its evolution into rock ‘n’ roll.

Moving backward in time from her ’60s homage to the Supremes in “Dream Girls,” “Cadillac Records” steps back into the ’40s and ’50s with Chess Records.

Focusing on Leonard Chess (and virtually ignoring his partner and brother Phil), “Cadillac Records” shows the growing record industry and the stars responsible for huge strides in music. Muddy Waters features prominently as laying the foundation for modern music along with Willie Dixon, Little Walter and Howlin’ Wolf. Etta James and Chuck Berry move in hot on their heals with a new sound of their own.

This is a good story about the music and an excellent showcase for performances of that music. The acting doesn’t quite sing, though. Adrien Brody is a serviceable Len Chess, and Jeffrey Wright manages as Muddy Waters. However, I don’t quite feel as if I “know” either luminary through their performances. Beyonce shines as Etta James. She’s not Oscar material yet, but she does have an excellent scene as a smack addict addled by an overdose, personal psychological demons and lust.

The costumes, recreated era and cars are amazing. Yet despite all of the accurate trappings of the ’40s and ’50s, something falls a little flat. It is partly the issue of race, partly an issue of disconnect between the way people acted in that era compared with the way the actors thought people acted back then and it is partly an issue of writing that tells too much without showing. Racial discord and reconciliation is heavily discussed but it is not made an ingrain part of the movie’s inner life. Outside of formulaic after-school special style efforts to showcase racism and racial harmony, I don’t feel anyone in the movie (outside of the Howlin’ Wolf character, who is far too under utilized) lives with and owns that tension and anguish in their performance. Beyonce taps it a little as Etta James, but mostly keeps it at arms length.

In contrast, “Ray,” the Ray Charles bio pic, had greater character development and focus showing the racism, struggle and many other elements that were period accurate and more fully developed with regard to human nature and the reality of the times.

But that is where this review and “Cadillac Records” lose a little too much focus. The spotlight must be readjusted to the music. The music was meant to be and is the star of this movie. If you ignore the side dishes and concentrate on the main course, you won’t be disappointed.

As for me, I wonder where we’ll see Beyonce next. I can only imagine a Billie Holiday movie at this point. Billie is dangerous water to tread, though, as virtually no one can replicate her gut-wrenching, soulful inflection filled with the agony of a really hard life and an undeniable glimmer of hope for something better. But then again, I never would have guessed the singer of the infectious pop hit “Put a Ring on It” could have reached so far down inside herself to manage Etta James.

God bless the child who’s got her own, Beyonce.