Bemoan, if you want, the end of director John Singleton’s important-film phase.

But aside from the blistering Boyz n the Hood and the little-seen Rosewood, Singleton’s thematic hammers to the head were slightly less concussive and annoying than those of Spike Lee.

And what Singleton’s popcorn output — Shaft, 2 Fast 2 Furious and now Four Brothers — lack in directorial imprint, they made up for with a rampaging sense of street-level entertainment.

Singleton’s latest isn’t just a loose reworking of The Sons of Katie Elder. It’s also a slapstick comedy with graphic violence, a revenge drama with identifiable grief and a police procedural hung on the social-issues hook of urban redevelopment.

It’s also not without its problems. Supporting characters played by Terrence Howard and Chiwetel Ejiofor exhibit stronger traits than any of its leads — a true waste given the natural charisma of Mark Wahlberg, Tyrese Gibson and Andre Benjamin.

Only swelling strings are missing from the mawkish visions of Mom each brother has at the dinner table. Plus, the film strays a bit from its promised finesse of intelligence and words in a climactic fistfight finale.

Still, the usually sharp script builds in silences that are covered by the laughs it earns, namely from Ejiofor. His Vincent Sweet is a street kingpin who’s like a comic version of New Jack City’s Nino Brown. While not quite the psychotic firecracker Jeffrey Wright was for a similar role in Singleton’s Shaft, Ejiofor provides energy that lingers even when he’s off-screen.

Plus, it sustains a solid amount of suspense and surprise. At least if Benjamin, all but absent from the middle act of the film, was off shooting another project much of the time, the movie nicely messes with our narrative perception of it.

One-half of OutKast plays Jeremiah, one of four adopted brothers — two black, two white — who reunite after the puzzling, brutal murder of their mother, Evelyn (Fionnula Flanagan). A tough old cookie who helped find homes for troubled kids, Evelyn took in these four when no one else would.

Attempting to be a property owner, Jeremiah has stayed in Detroit, where pick-up games are hockey and snow is packed thick and piled high. But ersatz leader Bobby (Wahlberg), muscular ladies’ man Angel (Gibson) and picked-upon baby bro Jack (Garrett Hedlund) return after prolonged absences. And they don’t mind a little vengeance along with answers to the murder.

As they proceed, their investigation grows both more conspiratorial and violent in occasionally unexpected bursts. Blood pools in the mouth of a shooting victim, one nasty protruding leg bone is compared to a “Chinese spare rib” and the cold aftermath of a bad-traction car chase is a stunner. That chase, by the way, is one of summer’s most fierce, fluid action sequences.

There also are plenty of circumstantial laughs in the brothers’ brand of detective work, especially in their disruption of a high-school basketball game for crucial information.

Those looking for the best crime thriller set in Detroit should trek to the video store and pick up Out of Sight. And Singleton no longer speaks as eloquently to his black audience’s larger experience as he has in the past. But there certainly could be, and have been, worse directors who have switched focus to B-pictures with just the right amount of substance.