Getting the Lead out
Fans of any music genre will want to catch "Legend of Lead Belly," a fascinating documentary on a man who was one of the most influential artists of the 20th century, inspiring everyone from the Beatles to Nirvana. Van Morrison and Roger McGuinn are among the musicians weighing in. 7 p.m. Smithsonian Channel
Can't we all just get along?
Emmy-winning journalist Tony Harris has teamed up with the Southern Poverty Law Center to investigate "Hate in America," a documentary that examines hate groups ranging from neo-Nazis to anti-government militias, all still thriving in the country. 7 p.m. Investigation Discovery
Oscar nominee "Citizenfour" takes a look at the early emergence of Edward Snowden as he began leaking classified government documents to journalists. It's an important story, but the film takes place largely in a Hong Kong hotel — not exactly a thrilling location — and director Laura Poitras comes off as a little too smug. 8 p.m. HBO