I went to a workshop yesterday, taught by Wylie Gustafson who believes that everyone can yodle. Not so sure about that, but I reckon everyone can try....
Gustafson grew up in Montana, and has been yodling for 30+ years. Yesterday he was teaching kids, employing creative teaching tools such as, among others, the "knock-knock yodle":
Little old lady.
Little old lady who?
Can you hear the last line sung as a yodle?
Gustafson's yodle is arguably the most widley heard yodle, ever. In the history of the planet earth. Really. Just go here, and click on the exclamation point at the top of the page.
The kids were enrapt with Gustafson's playing and singing. And the ranks of his army of yodlers (with whom he planst take over the world, at some point) grew a dozen or so stronger yesterday morning.