When singer-songwriter Marvin Gaye died in 1984, he left behind one of the great legacies in American music. More than a superb vocalist and subtle composer, he was a visionary who expressed the tenor of his times. Both radical and romantic, a self-taught singer with a flair for autobiographical revelation, he thrived on confession and loved candor. Along with clips of Marvin both on and offstage, the PBS documentary WHAT’S GOING ON (2008, 60 min) features interviews with artists such as Smokey Robinson, Gladys Knight, and Mos Def.