G'day,
So are "Ye Banks And Braes" (Burns) and "Nottamun Town" (and therefore Dylan's "Masters of War"). I understand that many tunes from the Southern Appalachian area are pentatonic.

Pythagoras (who first realized that the squaw on the hippopotamus' hide was equal to the squaws on the other two hides) was also (possibly) the first to express music in mathematical terms (by noting that the frequency or pitch of one note is 9/8 that of the next etc. and that an octave is a doubling of frequency. He also described the intervals of a third and fifth). It appeared to me when I read about this many years ago that he described a pentatonic scale, i.e. none of the intervals he described were semitones (15/16 ).

Cheers,
Alan