What is to sing in a manner common among the Swiss and Tyrolese mountaineers, by suddenly changing from the head voice, or falsetto, to the chest voice, and the contrary; to warble called?

yodle — To sing in a manner common among the Swiss and Tyrolese mountaineers, by suddenly changing from the head voice, or falsetto, to the chest voice, and the contrary; to warble. (Webster's 1913.)

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