James Brown biopic Get On Up revels in drama

At first Oscar-winning actress Octavia Spencer thought she was seeing early concert footage of James Brown but then was told it was a screen test by Chadwick Boseman to play the "Godfather of Soul" in the new biopic Get On Up.

From the gliding, intricate footwork to the hunched shoulders and fluid movements, Boseman had nailed Brown's singular mannerisms and raspy voice.

"It was just him from the back, and then from the side, and it was all in silhouette with the hair. I could not believe it, and he had only been learning the dance for three days," says Spencer, 44, who plays Brown's no-nonsense, knife-wielding Aunt Honey in the film, which opens in US theaters on Friday.