The Song of Night.

He was known as Anatole Litvak during his Hollywood directorial career, but he was still Anatole Litwak when he helmed the German musical Das Lied Einer Nacht (The Song of Night). Famed Polish tenor Jan Kiepura stars as famed Italian tenor Ferraro. Escaping from his tyrannical manager, Ferraro switches identities with a young tourist (Fritz Schulz) and goes off on an unscheduled Swiss holiday. Still travelling incognito, our hero falls in love with a winsome mountain girl (Magda Schneider). Alas, both his romance -- and his freedom -- are placed in jeopardy when it turns out that the charming young fellow with whom Ferraro traded identities was actually a notorious swindler. Anatole Litvak also directed the English-language version of Das Lied Einer Nacht, Be Mine Tonight