Yodeling is a form of singing that involves singing with repeated changes in pitch from the chest register to the head register without using words that mean anything. As described this way, yodeling is spread worldwide. It is especially in mountainous and inaccessible regions that natural yodeling communication forms have developed in order to communicate from one hill to the other or to bring in the cows. Although yodeling was probably being used back in the Stone Age, the choir singing of the yodeling songs only developed in the 19th century.
Yodeling songs of the natural yodelers When a solo yodeler starts to sing a slow sequence of notes, the other yodelers hum along with the appropriate tone, and provide a spontaneous melody – resulting in natural yodel singing. In this primitive way, in the various mountain regions of Switzerland, one-to five-part yodeling songs are sung without words. In the Muota Valley, the "Jüüzli" is sung with two or three voices, while the Appenzell "Zäuerli" and "Ruggusserli" are polyphonic natural yodels that are often spontaneously improvised. During festivals and special occasions polyphonic natural yodels are often accompanied by talerschwingen or bell shaking (small Alpine bells). What makes the natural tones of the natural yodel so special is the eleventh tone, the natural tone, or alphorn Fa. This unique tone in C major is neither heard as "F" nor as "F sharp" but is somewhere in between. For many people, this "Fa" can be hard to get used to because since the 18th century, when "well-tempered" tuning was introduced, this sound has disappeared from the usual tone series.
Yodel choirs and yodel songs In Switzerland and the other Alpine countries, yodeling developed into song in the 19th century. The yodel song, now with a two, three and four-part harmony, and usually accompanied by a "Schwyzerörgeli" (accordion) is the genre most favoured by yodelers in associations. In 1910, these merged into the Swiss Yodeling Association. Each year they perform in front of the jurors in regional and cantonal yodeling festivals and every three years in a national yodeling festival. The songs are about the mountains, nature and home, and also include issues such as freedom and independence. Since 1971, spiritual yodeling songs have also been sung at festivals. Today there are about 2,000 compositions of Swiss yodeling songs, mainly in German, but also in French. Yodeling is now no longer really practiced in the Italian and Romansh-speaking areas of the country, and if so, predominantly German-language songs are sung.