The equal multiplication of 33/32, the Alpharabian quarter-tone, results in an interesting nonoctave tuning, equivalent to 22.5255 EDO.

Lookalikes: 5ed7/6, 45ed4

Theory

Approximation of prime harmonics in 1ed33/32
Harmonic 2 3 5 7 11 13 17 19 23 29 31
Error Absolute (¢) +25.3 +15.9 -16.1 -12.6 +4.0 -18.9 -3.8 +16.7 +5.6 -22.8 +21.5
Relative (%) +47.4 +29.8 -30.3 -23.7 +7.5 -35.4 -7.2 +31.3 +10.4 -42.8 +40.4
Step 23 36 52 63 78 83 92 96 102 109 112

In this tuning, 2 steps correspond to the parapotome 1089/1024, and 5 steps are approximately equal to 7/6, thus tempering out the quartisma if this equivalence is assumed.

Intervals with excellent approximation in this tuning are: 7/6, 18/11, 20/13. Other intervals with good approximation are: 6/5, 7/5, 9/5, 13/7, 13/9, 11/10, 19/12, 17/16, 17/15, 16/15.