Marlene Dietrich in "The Blue Angel"

Der Blaue Engel (1930) was the first sound film ever made in Germany. It's also the movie that rocketed Dietrich, as the cabaret singer Lola Lola who headlines at "The Blue Angel," to international stardom.

It's also the first film in which she sings Falling in Love Again, which became a Dietrich trademark over the years.

Related:

A review of Josef von Sternberg's The Blue Angel, which includes this tantalizing tidbit:

Greta Garbo possessed some of the same qualities as Marlene Dietrich, but Garbo brought a more introspective quality to her performances. Dietrich's innate bitchiness was always part of the characters she played. Like Dietrich, Garbo had a seemingly cool exterior, but this coolness was balanced by a faint-but-discernible smoldering sense of warmth. Dietrich was rarely warm but her magnetism has become legendary.

Listen to Dietrich music clips here.