Yodeling (also jodeling) is a form of singing which involves repeated and rapid changes of pitch between the low-pitch chest register (or "chest voice") and the high-pitch head register or falsetto. The English word yodel is derived from the German word jodeln, meaning "to utter the syllable jo " (pronounced "yo"). More @Wikipedia
Hover over any link to get a description of the article. Please note that search keywords are sometimes hidden within the full article and don't appear in the description or title.