Everyone knows it and it was shown in cinema like this: alle 11 million Bavarians wear Lederhosen, Dirndl und Gamsbarts.
And all, all yodel by any occasion. Good. In the same row would this argument stand: fresh water is only in Bavaria.
Proof: fresh water rains from the sky and collects always in the valley. Thus all valleys are full with water. Thus humans can only live on hills. All hill inhabitants are yodeling. due only the bavarians yodel, only there is fresh water...
It is always confusing, which stereotypes of typical for a nation is included against every truth. Only after longer studies one learns to know that there were originally two forms of yodlers: the call and the song.
The call is a more complicated, under slalom circumstances said signal scream. Ist purpose was to communicate with someone else over long distances from hill to hill. The second, main form is a multiple voice song with no text.