The Voice of the Heart(1937)

Original title: Die Stimme des Herzens

A princess visiting in the hotel where a famous singer is staying,helps him out on the piano when he has dismissed his accompanist. he uses her again later,but when her betrothed,a prince,suspects her of being in the singer,s bedroom she runs away to another city to work incognito.But the singer turns up there as well and reconciles the lovers.