← 127edo 128edo 129edo →
Prime factorization 27
Step size 9.375 ¢ 
Fifth 75\128 (703.125 ¢)
Semitones (A1:m2) 13:9 (121.9 ¢ : 84.38 ¢)
Consistency limit 7
Distinct consistency limit 7

Template:EDO intro It is notable for being the equal division corresponding to a standard MIDI piano roll of 128 notes.

Theory

The equal temperament tempers out 2109375/2097152 (semicomma) in the 5-limit; 245/243, 1029/1024 and 5120/5103 in the 7-limit; 385/384 and 441/440 in the 11-limit. It provides the optimal patent val for 7-limit rodan, the 41 & 87 temperament, as well as for 7-limit fourfives, the 60 & 68 temperament.

See also 128 notes per octave on Alto Saxophone (Demo by Philipp Gerschlauer)

Prime harmonics

Approximation of prime harmonics in 128edo
Harmonic 2 3 5 7 11 13 17 19 23 29 31
Error Absolute (¢) +0.00 +1.17 -1.94 -3.20 +1.81 +3.22 -1.83 +2.49 -0.15 +1.67 -1.29
Relative (%) +0.0 +12.5 -20.7 -34.1 +19.3 +34.4 -19.5 +26.5 -1.6 +17.8 -13.7
Steps
(reduced)
128
(0)
203
(75)
297
(41)
359
(103)
443
(59)
474
(90)
523
(11)
544
(32)
579
(67)
622
(110)
634
(122)

Subsets and supersets

Since 128 factors into 27, 128edo has subset edos 2, 4, 8, 16, 32, and 64.

Regular temperament properties

Template:Rank-2 begin |- | 1 | 25\128 | 234.375 | 8/7 | Rodan |- | 1 | 29\128 | 271.875 | 75/64 | Orson |- | 1 | 33\128 | 309.375 | 448/375 | Triwell |- | 1 | 53\128 | 496.875 | 4/3 | Undecental |- | 2 | 13\128 | 121.875 | 15/14 | Lagaca |- | 2 | 15\128 | 140.625 | 27/25 | Fifive |- | 4 | 15\128 | 140.625 | 27/25 | Fourfives |- | 4 | 53\128
(11\128) | 496.875
(103.125) | 4/3 | Undim (7-limit) Template:Rank-2 end Template:Orf

Scales