Yodeling (or yodelling, jodeling) is a form of singing that involves singing an extended note which rapidly and repeatedly changes in pitch from the vocal or chest register (or "chest voice") to the falsetto/head register; making a high-low-high-low sound. This vocal technique is used in many cultures throughout the world.

HISTORY

In Alpine folk music, it was developed in the Central Alps as a method [bad word] between alpine mountaineers or between alpine villages, with this non-musical multi-pitched "yelling" later [bad word] part of the region's traditional lore and musical expression.

In Persian classical music, singers frequently use tahrir, a yodeling technique that oscillates on neighbor tones.

In Georgian traditional music, yodelling takes the form of krimanchuli technique, and is used as a top part in three/four part polyphony.

In Central Africa, Pygmy singers use yodels within their elaborate polyphonic singing, and the 
Shona people of Zimbabwe sometimes yodel while playing the mbira. 
Yodeling is often used in American bluegrass and country music.

According to the Oxford English Dictionary the word yodel is derived from a German word jodeln (originally Austro-Bavarian language) meaning "to utter the syllable jo".