“A pentatonic scale is a musical scale with five pitches per octave in contrast to an heptatonic (seven note) scale such as the major scale. Pentatonic scales are very common and are found all over the world, including but not limited to Celtic folk music, Hungarian folk music, West African music, African-American spirituals, Jazz, American blues music and rock music, Sami joik singing, children's songs, the Greek traditional music and songs from Epirus, Northwest Greece and the music of Southern Albania, the tuning of the Ethiopian krar and the Indonesian gamelan, melodies of Korea, Japan, China and Vietnam (including the folk music of these countries), the Afro-Caribbean tradition, Polish highlanders from the Tatra Mountains, and Western Classical composers such as French composer Claude Debussy.”

[http://en.wikipedia.org/wiki/Pentatonic_scale]