The remaining Thursdays in May are devoted to the films of Marlene Dietrich, so clear space on your DVRs and strap yourself in. I long knew about her iconic role as a cabaret temptress in 1930’s The Blue Angel, which begins the salute at 8 p.m. ET, but a college film class introduced me to 1934’s The Scarlet Empress (up next at 10 p.m. ET, pictured), in which she plays the kinky and powerful Empress of Russia. Josef von Sternberg directed them both, with a clear gift and appetite for the salacious – and also directed the other Dietrich showcases, and stunners, on tonight’s TCM schedule: 1932’s Shanghai Express at midnight ET, 1930’s Morocco at 1:45 a.m. ET, and 1932’s Blonde Venus at 3:30 a.m. ET. Watch them all. When designing her music videos, Madonna sure did…