A silent film character is stuck in a German theater and wants to return to his film.

Kathrin, Sylvio, and Pierre are music students in Paris. Due to their financial difficulties, the bailiff Fogar is even forced to seize their musical instruments. However, he allows them to continue practicing with them in his warehouse. There, the trio meets the composer Duval, who is also struggling financially.

The chorus girl Caterina Duval gets the chance of her life when hired as stand-in of a famous star. On the opening night Catarina is singing, dancing and stepping into the hearts of the audience.

Several young music enthusiasts find a helpful supporter of their passion—singing and making music—in the endearing, friendly elderly gentleman Mr. Herzlieb, who works as a night watchman at a pawnshop specializing in musical instruments. Using a shortwave transmitter, they are even able to broadcast their pop songs all the way to Brazil, after which the music lovers are offered a gig. A German "Schlager-Film" (a musical comedy with popular songs).