*It’s no coincidence that “Marley,” the critically-acclaimed new Bob Marley documentary, wafts into theaters (and On Demand) on April 20 – the unofficial holiday celebrating marijuana.

Director Kevin Macdonald said it was the studio’s idea to release the biopic on this day as a marketing tool. The film itself, however, delves much deeper than the singer’s pop culture image as a weed-smoking reggae legend.

The film shows how Marley was a savvy businessman, as well as a competitive dad that wouldn’t let even a first-grader win in a foot race. We see the horrifying poverty that surrounded him (he was born in a one-room shack to a Jamaican teen mother and white 60-year-old captain in the British marines), and how he dealt with the social stigma of being bi-racial and Rastafarian.

“Marley,” which has the full blessing of his family, is packed with rare footage, vintage performances and revelatory interviews with the people that knew him best.

Ziggy Marley in a still from the documentary "Marley"

Bob Marley’s son Ziggy – who appears in the film with his siblings and serves as an executive producer – says this documentary should now be considered the one and only “definitive” story of his father’s life.

“Definitive, meaning that everything else is secondary to this piece here,” Ziggy told us during interviews for the film this week. “[Out of] everything that has been done, every book that has been written – this documentary is the pinnacle of it all.”

Below, Ziggy explains how he came to discover a different side of his famous father during the course of production.  [Scroll down to watch the trailer.]