Quote Originally Posted by beloitpiper View Post
Scottish folk music, and indeed the bagpipe, is in the pentatonic scale. So is most Native American music. As is Greek, Vietnamese, Hungarian, Ethiopian, and Polish folk music. As an anthropologist who dabbles in ethnomusicology, I have wondered why the pentatonic scale seems so universal in folk and "primitive" music. Well this isn't the answer, but it sure does make you think.

http://www.boingboing.net/2009/08/01...rin-hacks.html

Truly the universal language.
It's because leading tones are so hard to sing in tune!

Really, the pentatonic scale is much easier to sing descending than are other scales. It probably has something to do with there being no leading tone, or subtonic.
Also, when the melody moves from V to I, everyone feels the strong cadence and knows they've arrived at tonic together. That is, when the melody cadences to I, and not to V!