Ball at the Savoy (1935)

Operetta star Gitta Alpar plays a singer engaged for a performance at the Savoy Hotel, where she mistakes Baron von Wollheim for a waiter. But the baron is content to play the game for a while and changes his role with the real waiter. Of course the singer is quite happy when she discovers the real identity of the baron, but now she mistakes him for a thief, as her necklet has gone missing. Further complications arise when the baron's cousin Mary, a composer, arrives at the hotel and wants a music publisher to listen to her songs.