128edo

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Revision as of 02:42, 30 October 2022 by Royalmilktea (talk | contribs) ((forgot edit summary) rank-2 temperaments)
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← 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 introIt is notable because it is the equal division corresponding to a standard MIDI piano roll of 128 notes.

Theory

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)

It is the optimal patent val for 7-limit Rodan temperament. It tempers out 2109375/2097152 in the 5-limit; 245/243, 1029/1024 and 5120/5103 in the 7-limit; 385/384 and 441/440 in the limit. Being the power of two closest to division of the octave by the Germanic long hundred, it has a unit step which is the binary (fine) relative cent (or relative heptamu in MIDI terms) of 1edo.

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

Regular temperament properties

Rank-2 temperaments
Periods

per octave

Generator

(reduced)

Cents

(reduced)

Associated

Ratio

Temperaments
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)

Scales