There’s a delicious moment in "Get On Up," Tate Taylor’s new James Brown biopic, when Brown — played by Chadwick Boseman, in a thrillingly magnetic performance — is about to appear on the T.A.M.I. Show, a multi-act concert filmed in 1964.

Backstage, the singer is informed that he and his band won’t be closing the show; that honor will be going to an up-and-coming British band called the Rolling Stones. Brown shakes off the disappointment, goes out and blows the roof off the place with the force of those growling vocals and explosive, kinetic dance moves. Then he saunters over to the Stones, five skinny blokes who don’t know what just hit them. "Welcome to America," he says.

Did he say that in real life? No matter. The scene illustrates Brown’s most important qualities: his indescribable drive as a performer, and his almost blinding charisma.

For that, kudos go to director Taylor and producers Brian Grazer and Mick Jagger (yes, that Mick Jagger, who’s made no secret of Brown’s influence on his own famous moves). But none of it would work, of course, without Boseman, an actor on a remarkable run of late, playing Jackie Robinson in "42" and now this. If he was impressive as the dignified Robinson, he’s electrifying as Brown.

And just as Brown, in life, upstaged pretty much everyone — including his band mates, the Famous Flames — Boseman does that here. The always excellent Viola Davis plays Brown’s mother, Susie, but since Susie left her son as a boy, we don’t see enough Davis — just a few sad moments from Brown’s hardscrabble rural youth, and then one excruciating, wonderfully played scene later, when she comes to see her adult son backstage at Harlem’s Apollo Theater.

‘GET ON UP’ Rated: PG-13 Opens Friday

The central relationship in Brown’s life, though, was with his friend and partner, Bobby Byrd, who stuck with him even as Brown’s ego pushed many away. As Byrd, Nelsan Ellis gives a thoughtful performance that, appropriately, grounds the film. (As Brown’s longtime manager, Dan Akyroyd occasionally gets a little hammy.)

Many biopics of performers follow a grating formula: tough youth, obstacles overcome, fame discovered, more obstacles, descent into old age or worse. Here, Tate and talented screenwriters Jez Butterworth and John-Henry Butterworth avoid this by jumping around in time, ditching chronology for a thematic approach. It can get confusing, but it keeps us on our toes.

They also have Brown break the fourth wall at key moments. Alas, this isn’t done early or frequently enough to feel coherent. Perhaps there just wasn’t time; even at 138 minutes, the film has to barrel though parts of Brown’s long public life. (He died in 2006, at 73.)

Luckily, there was time for the scene in which an older Brown bursts into a meeting at a building he owns, shooting at the ceiling with a rifle; he’s annoyed someone used his private bathroom. Also memorable: the scene in which Brown encounters a young Little Richard (Brandon Smith, highly entertaining), and Brown’s amusingly incongruous appearance in a ski sweater in the 1965 Frankie Avalon film "Ski Party."

Much more harrowing is a scene showing Brown hitting his second wife, DeeDee — a brief evocation of the man’s darker side.

Also effective is a tense scene in which Brown forces his band, in rehearsal, to change the sound they’re used to playing. They resist; he wins. And the music does sound fabulous throughout; one imagines Jagger had something to do with that. (The vocals in the film are Brown’s; as for the dance moves, that’s all Boseman.)

In the end, we have a portrait that is not uniformly positive — Brown was too complicated for that — yet falls mostly on the kinder side. At one point, Byrd is trying to explain to a frustrated band mate why he sticks with Brown.

"He’s a genius," Byrd says simply.

True enough.

Review by Jocelyn Noveck, Associated Press