theorem Th68: :: MUSIC_S1:88

for MS being MusicSpace
for frequency being Element of MS
for r1, r2, r3, r4, r5, r6 being positive Real st (pentatonic_pythagorean_scale (MS,frequency)) . 1 = r1 & (pentatonic_pythagorean_scale (MS,frequency)) . 2 = r2 & (pentatonic_pythagorean_scale (MS,frequency)) . 3 = r3 & (pentatonic_pythagorean_scale (MS,frequency)) . 4 = r4 & (pentatonic_pythagorean_scale (MS,frequency)) . 5 = r5 & (pentatonic_pythagorean_scale (MS,frequency)) . 6 = r6 holds
( r2 / r1 = 9 / 8 & r3 / r2 = 9 / 8 & r4 / r3 = 32 / 27 & r5 / r4 = 9 / 8 & r6 / r5 = 32 / 27 )