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.