This film (also screening on August 28th and 31st) is part of the BFI Southbank's Big Screen Classics Season. You can find all the details here.
Chicago Reader review:
The first film collaboration between Josef von Sternberg and Marlene Dietrich (1930), this reeks with decay and sexuality. Emil Jannings plays the professor who tries to stop his students from visiting nightclub singer Lola-Lola (Dietrich) and ends up succumbing to her plump charms. In many ways the film is about the constancy of emotion as well as the destructive tricks it plays. Jannings's repressed little prig, whose first sexual encounter results in his total destruction, is redeemed from contempt by Sternberg's respect for his masochistic passion. In German with subtitles.
Here (and above) is an extract from the film.