84edo

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Revision as of 18:21, 13 September 2022 by Eliora (talk | contribs) (enrichment with information, emphasizing relation to orwell, i'll add relative error later because it isn't simply absolute calibrated to edo size, it's by complexity)
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← 83edo 84edo 85edo →
Prime factorization 22 × 3 × 7
Step size 14.2857 ¢ 
Fifth 49\84 (700 ¢) (→ 7\12)
Semitones (A1:m2) 7:7 (100 ¢ : 100 ¢)
Consistency limit 7
Distinct consistency limit 7

84edo divides the octave into 84 equal parts of size 14.286 cents each.

Theory

Its patent val 84 133 195 236 291] makes it an excellent orwell tuning and also a good one for compton, and the 84e val, 84 133 195 236 290], is almost identical to the 11-limit POTE tuning for orwell. In the 13-limit it is the optimal patent val for the rank five temperament tempering out 144/143.

84edo is where the orwell temperament takes its name from, since the generator of 7/6 is equal to 19 steps of the EDO, referencing the book 1984. The maximum evenness orwell in this temperament is a 31 note scale, and other MOS are of size 9, 13, and 22. Orwell in 84edo comes in two varieties - 31e & 84, being the proper orwell, and 31 & 84, being newspeak.

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Table of intervals

For this table, the notation of Orwell[9] from the 4L 5s page is taken. Notes are denoted as LsLsLsLss = JKLMNOPQRJ, and raising and lowering by a chroma (L − s), 3 steps in this instance, is denoted by & "amp" and @ "at".

Table of 84edo intervals
Step Size (Cents) Orwell note

(if tonic is J)

Orwellian Name Associated ratio
0 0.000 J unison, prime 1/1 exact
3 42.857 J&
11 157.143 K second
19 271.429 L third 7/6
22 314.286 L& major third
30 428.571 M fourth
38 542.857 N fifth 11/8 in the 84b val
41 585.714 N&
49 700.000 O sixth 3/2
57 814.286 P seventh 5/3
60 857.143 P& 105/64
68 971.429 Q eighth
76 1085.714 R ninth
79 1128.571 R&
84 1200.000 J (tenth above) perfect tenth 2/1 exact

Regular temperament properties

Subgroup Comma list Mapping Optimal

8ve stretch (¢)

Tuning error
Absolute (¢) Relative (%)
2.3.5 78732/78125, 531441/524288 84 133 195] 0.498 0.531
2.3.5.7 225/224, 1728/1715, 321489/320000 84 133 195 236] 0.141 0.769
2.3.5.7.11 225/224, 441/440, 1944/1925, 8019/8000 84 133 195 236 291] -0.225 1.003
2.3.5.7.11 99/98, 121/120, 1728/1715, 321489/320000 84 133 195 236 290] (84e) 0.601 1.151

Scales

Music