The film which was released in 1930 had propelled Marlene Dietrich (and her singing and her legs) to the international stardom. But the film belongs to Emil Jannings in the role of the respected, straight-laced, balding, aging, and portly High School English Professor who became absolutely obsessed by Dietrich's Lola - a cabaret's singer and dancer. His first step toward cabaret "The Blue Angel" was his first step to humiliation, madness, ruin, and ultimately, death. It is not the first time in the history or in Art when a man falls for a wrong (for him) woman ("Carmen", anyone?) and loses his mind, his status, and his life because of her but it is certainly one of the most heartbreaking stories that started as a light musical comedy and came to the sad but inevitable ending.
Review of Der blaue Engel
