To use PythagoreanMajor, you first need to load the Music Package using Needs["Music`"].
Intervals are measured in cents.
MusicScale[PythagoreanMajor, freq, dur] creates a Sound object that is a sequence of pitches corresponding to the Pythagorean Major scale.
PythagoreanMajor has an interval list in which the members of the scale are derived from a sequence of octaves and fifths, where a fifth is the ratio of 3/2 (702 cents) and an octave is the ratio of 2/1 (1200 cents).
The scale is built by successive fifth addition and octave subtraction.
