“Get on Up” is loud, proud, funky, soulful, sweaty, emphatic and sometimes a little hard to understand, just like its subject, James Brown.

Another point of similarity: It gives 110 percent and doesn’t stop till we’re entertained to the point of wrung-out exhaustion. Brown played 350 shows a year at his peak, and launched more than 40 Billboard hits. Tate Taylor’s musical biography has the same insatiable drive, rocketing us along a roller coaster of awe, admiration, pity and repulsion.

It never quite cracks the mystery of how James Brown rocketed from the Jim Crow South to become the screaming, moaning, gymnastic Godfather of Soul. But it puts on one hell of a show. The inevitable soundtrack album should be a cornerstone of soul-music collections.

“Get on Up” bites off a huge chunk of Americana, covering a half-century of poverty, segregation, politics and the music business. The screenplay is a collection of Greatest Hits moments from Brown’s life. It’s less concerned with coherence and focus than rhythm and flow, shuffling chunks of chronology around until they make the most interesting counterpoints. The film begins at the end with Brown’s unhinged, disheveled gun-toting final years. Then it leaps back to the rural deprivation and unstable parenting of his childhood, ahead to the Vietnam War, then sideways to record-industry racism in the ’50s. Confused yet? You will be.

Still, how can you straighten out a tumultuous tangle of contradictions like Brown? He was a Black Power icon who befriended Strom Thurmond. A perfectionist who smoked PCP.

Taylor (“The Help”) doesn’t allow his film to marinate in Brown’s lifelong legal troubles, but he doesn’t sideline them, either. The movie doesn’t pretend that lovability was one of Brown’s main characteristics. We see him deliver a beating or two, fine and fire his band members for trivial or imagined offenses. When he impatiently tries to explain the harmony in his head without the musical vocabulary, his sax man Maceo Parker (Craig Robinson) frowns in ill-disguised contempt. And we sympathize.

Chadwick Boseman (“42”) is too handsome and long-legged to be a convincing physical embodiment of Brown, a compact, muscular little rooster with a tough mug. Kevin Hart’s more the type. But Boseman digs into Brown’s spiky character, celebrating his musical genius without idealizing him. He radiates the swagger and me-first drive it takes to become a pop star. He’s breathtaking busting out a flamboyant front-stage split or a crazy-legged shuffle-shoe Mashed Potato. He’s blazingly alive. When he performs, he performs.

He also accurately mimics Brown’s mumbling, mush-mouthed speech patterns. Not since Batman’s Bane strapped on his facemask have I had such a tough time following a movie character’s dialogue. The film shows Brown responding to inane press questions with cryptic gobbledygook. Speech wasn’t Brown’s mother tongue, song was. But genius will not be denied, and Brown managed to howl out a thunderous catalog of hits that power “Get on Up” to rare heights.

While the movie notes plenty to criticize in Brown’s makeup, there’s also much to respect. He deftly negotiated the vagaries of the music world when separate strands of white and black pop merged. In one priceless vignette, Brown and his sidemen play on a peachy-keen ’60s holiday special with vapid kids in snowflake cardigans. Under his breath, he marvels “I’m in some kinda honky hoedown.” But he still gives the show his all. Brown was nicknamed the hardest working man in show business, and this powerhouse biography gets a well deserved A for effort.