I saw a splendid play (whose title I can't recall) a few years ago that dealt with some of country music's roots. It was set in Appalachia and included dozens of songs. It mentioned yodeling as a means of communicating across great distances in the mountains--a shout wouldn't carry very far but a yodel would, and this could be a lifesaver in certain emergencies.

One character in the play, a traditionalist, took offense at another character's use of yodeling in entertaining. Apparently he found this insulting to the serious and necessary nature of yodeling in real life.