The calypso star-turned-social activist agreed to let cameras into his life for the new documentary film Sing Your Song, which chronicles his longstanding career and work with civil rights activists.
And Belafonte admits he wanted fans to see the other side of his legacy, because so much of Hollywood icon Brando's charity contributions are just forgotten memories.
He tells WENN, "What motivated me to do this documentary was Marlon’s death. He and I had grown up together. We lived a lot of life together and when he passed away, beyond losing a very good friend, I also know that America lost not only a great artist but someone who had touched deeply the search for our humanity as a society.
"He’d given himself to many causes that represented the struggle for those who are underserved and undernourished and our country and our world knew very little about that part of his life."
But Belafonte confesses it took him a while to put his plan into action - and it took his daughter's constant nagging to finally push him to tell his story on film.
He says, "My daughter Gina was the nag of the family. She constantly put upon me that I should really document my story and that I should tell it, and my reluctance to delve into that was because I felt it was somewhat self serving.
"On Marlon’s death (in July, 2004), I saw opportunity to reach in to try to tell the story of Marlon and a number of other people who are in the film to help guide the viewer through some corners and twists and turns that may not be known to them."