Mick Jagger was “blown away” by James Brown.

The 71-year-old musician serves as producer through his company Jagged Films for Get on Up, a biopic on the life of James Brown. The rock legend was heavily involved in the film, working on everything from the casting to the storyline to the choreography. However, the movie wasn’t just a job for the star but a personal experience.

"You can hear that he's a great performer, and I was picturing how he would dance,” The Rolling Stones singer recalled the first time he heard James sing in singles such as Try Me and Think! in an interview with USA Today. “Then I went to see him at the Apollo and I was blown away. I was impressed by how hard he worked and how he had the audience in the palm of his hand. That was a learning experience for me."

Mick and James became friends after a show at the Harlem theatre. The Godfather of Soul was always “very generous” but he “talked about business a lot”, which Mick admits wasn’t what he was interested in.

"James was definitely one of those guys with super drive and energy,” Mick explained to the publication. "He stayed in shape all the time. He never left the audience bored. He involved the audience and kept them amused and entertained. He gave his best in every show."

Mick, who is on a break from The Rolling Stones 14 On Fire tour, was inspired by James and when the opportunity came eight years ago to work on the film, he was excited to take it.

James passed away in 2006 at the age of 73. He is played by Chadwick Boseman in the film, which will be released on August 1.