Die vom Rummelplatz (movie, 1930)

Young Anny returns from school to her circus family, which runs a little venue at the town fair. When Anny suddenly has to fill in for one of the artists, her piano-playing not only enthrals the audience, but also theatre agent Hobbes. He casts the whole family for the Apollo theatre in Berlin, where Anny quickly raises to stardom and is offered an engagement from the US.