A documentary by Poull Brien. 19+ only. Opens Tuesday, August 6, at the Rio Theatre

If everything old becomes new again, Charles Bradley may be the youngest man in the U.S. Certainly, you need incredible stamina—plus talent, chutzpah, and patience—to make your mark at age 62, as this Brooklyn singer-songwriter did. To be black, poor, and illiterate only added to the challenges faced by the subject of this remarkable documentary.

Bradley, who still lives in a deplorable housing project, augmented his scattershot living with deft impersonations of James Brown at small clubs in the Northeast. Encounters with the neo-soul–minded folks at Daptone Records, who handle Sharon Jones and the Dap-Kings, led to collaboration with guitarist-producer Thomas Brenneck. And results included tour support for Jones and No Time for Dreaming, a debut album of Bradley originals that sold well and became one of Rolling Stone’s top albums of 2011.

Directed by first-timer Poull Brien, Charles Bradley: Soul of America covers the months leading up to that record’s release, with its fast-moving 75 minutes also devoted to the singer’s family history, which isn’t pretty.

He and numerous brothers and sisters were abandoned by their mother, who left Florida for New York City when Charles was an infant. A litany of disasters followed, but Bradley ended up looking after his now elderly mom and, apparently, ungrateful siblings. Without real encouragement, he somehow kept up his passion for singing. Eventually, his fealty to old-school R & B made him an artist distinctive enough to get attention in today’s ultrafragmented marketplace.

Sticking to an unfussy fly-on-the-wall style, with lots of rehearsals and highly emotional performances, the doc makes the case for an unknown man’s inspiring talent for music and for making friends. It also bears out the words to one of his best songs: “Why Is It So Hard (to Make It in America)?”