Ken Bowser's film biography of a seminal American protest singer of the '60s and '70s is conventionally told but also informative and moving. Ochs was a normal college kid at Ohio State University who discovered guitar and, soon after, folk music, and he never went back, dropping out for Greenwich Village. There he wrote angry ballads against Jim Crow and the Vietnam War and had a rivalry with fellow Midwesterner Bob Dylan. He worshipped Dylan; Dylan, however, was scornful of Ochs's protest music. The documentary does the usual weave of call-to-arms songs (including Ochs's flagship anti-war classic, "I Ain't Marching Any More") and newsreel footage, but it's most powerful in its sad last act. Ochs, who wanted to be America's premier songsmith, instead stumbles about in depression and alcoholism - and yet, in a moment of light, he travels to Chile to sing to miners when, miraculously, Salvador Allende takes power.