Hi,

The song is called "(Die) Dorfmusik", but it's also commonly know by the first line, being the first line of the chorus: Wenn am Sonntagabend die Dorfmusik spielt. The singers sound like the Comedian Harmonists. (I hesitate to say that it's really them as, like the video, the audio is lacking certain thirties characteristics. Either this is modern, or they did a really good job protecting this or cleaning it up.)

You can probably find both the schlager version and the Harmony version on the tube sites.

Bye,
                                                                  Mysha