AMC has greenlit National Anthem, an eight-episode musical anthology series created by Contagion writer Scott Z. Burns, and executive produced by Mark Johnson, who won an Oscar for Rain Man and a pair of Emmys for Breaking Bad, the network announced Tuesday. National Anthem is described as a tragically funny musical dramedy about a middle class midwestern family tumbling down the ladder of American society who periodically burst into song as they struggle to catch themselves. Oscar winner T Bone Burnett (Crazy Heart) is attached as the series' music producer, with words and music by Craig Finn of the …