Wilfried Schaum wrote ... The crucial difference between Oriental and European music is: Only the Europeans developed polyphony, and don't know the quarter tones which are common in the Orient. The European scales, of which only survived major and minor, are from early Greek origin. More old scales were preserved until medieval times in church music.

Not entirely true. Many of the "old" scales (Modes) remain in traditional melodies from the British Isles. The Scandanavians use quarter tones in their traditional music. I am sure there are other examples.

On of the flute tutors at Folkworks Summer School this year was from Sweden and as well as teaching us some traditional Swedish Tunes, she brought along some traditional flutes. One was superficially identical to an alto recorder (complete with thumbhole - and it responded to recorder fingering) but the seventh fingerhole was tuned a quarter tone sharp of F rather than the Fnat of a normal alto recorder. She said that the cadence on a G maj scale used this slightly sharp F rather than the normal F# normally used for the scale of Gmaj.