"Lasst uns froh und munter sein", ("Let us be happy and cheerful") is a traditional German Christmas carol from the Hunsrück/Taunus region. There are some regional variations in the lyrics. The song is traditionally sung on Nicholas Eve (Nikolausabend) on December 5, the evening before the feast of Saint Nicholas of Myra, December 6.
References
Lasst uns froh und munter sein Wikipedia(Text) CC BY-SA