45edo

From Xenharmonic Wiki
(Redirected from 45-edo)
Jump to navigation Jump to search
← 44edo 45edo 46edo →
Prime factorization 32 × 5
Step size 26.6667 ¢ 
Fifth 26\45 (693.333 ¢)
Semitones (A1:m2) 2:5 (53.33 ¢ : 133.3 ¢)
Consistency limit 7
Distinct consistency limit 7

45 equal divisions of the octave (abbreviated 45edo or 45ed2), also called 45-tone equal temperament (45tet) or 45 equal temperament (45et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 45 equal parts of about 26.7 ¢ each. Each step represents a frequency ratio of 21/45, or the 45th root of 2.

Theory

45edo effectively has two approximate major thirds, each almost equally far from just, but as the flat one is slightly closer, it qualifies as a meantone temperament, forming a good approximation to 2/5-comma meantone. It is a flat-tending system in the 7-limit, with 3, 5, and 7 all flat, but the 11 is sharp.

It provides the optimal patent val for flattone temperament, 7-limit rank-3 avicennmic temperament tempering out 525/512, the 11-limit calliope temperament tempering out 45/44 and 81/80, and the rank-4 temperament tempering out 45/44. It tempers out 81/80, 3125/3087, 525/512, 875/864 and 45/44. It is also the unique equal temperament tuning whose patent val tempers out both the syntonic comma and the ennealimma.

45edo tempers out the quartisma and provides an excellent tuning for the 2.7/3.33 subgroup direct quartismic temperament, in which it approximates the 33/32 quartertone with 2 steps and 7/6 with 10 steps. A bit more broadly, it maps the 2.17.25.27.33.63.65 subgroup to great precision; this is the part of the 17-limit shared with 270edo.

Otherwise, it can be treated as a 2.5/3.7/3 subgroup system (borrowing 5/3 from 15edo and 7/3 from 9edo) and is a good tuning for gariberttet, defined by tempering out 3125/3087 in this subgroup, approximating 2/5-comma gariberttet.

Odd harmonics

Approximation of odd harmonics in 45edo
Harmonic 3 5 7 9 11 13 15 17 19 21 23
Error Absolute (¢) -8.6 -13.0 -8.8 +9.4 +8.7 +12.8 +5.1 +1.7 -4.2 +9.2 +11.7
Relative (%) -32.3 -48.7 -33.1 +35.3 +32.6 +48.0 +19.0 +6.4 -15.7 +34.6 +44.0
Steps
(reduced)
71
(26)
104
(14)
126
(36)
143
(8)
156
(21)
167
(32)
176
(41)
184
(4)
191
(11)
198
(18)
204
(24)

Intervals

Step # ET Just (JI) Error
(ET−JI)
Ups and downs notation
Cents Interval Cents
0 0.000 1/1 0.000 0.000 Perfect Unison P1 D
1 26.666 65/64 26.841 -0.174 Up unison ^1 ^D
2 53.333 33/32 53.273 0.060 Augmented Unison A1 D#
3 80.000 22/21 80.537 -0.537 Diminished 2nd d2 Ebb
4 106.666 17/16 104.955 1.711 Downminor 2nd vm2 vEb
5 133.333 27/25 133.238 0.095 Minor 2nd m2 Eb
6 160.000 11/10 165.004 -5.004 Mid 2nd ~2 vE
7 186.666 10/9 182.404 4.262 Major 2nd M2 E
8 213.333 9/8 203.910 9.423 Upmajor 2nd ^M2 ^E
9 240.000 8/7 231.174 8.826 Augmented 2nd A2 E#
10 266.666 7/6 266.871 -0.205 Diminished 3rd d3 Fb
11 293.333 32/27 294.135 -0.802 Downminor 3rd vm3 vF
12 320.000 6/5 315.641 4.359 Minor 3rd m3 F
13 346.666 11/9 347.408 -0.741 Mid 3rd ~3 ^F
14 373.333 5/4 386.314 -12.980 Major 3rd M3 F#
15 400.000 63/50 400.108 -0.108 Upmajor 3rd ^M3 ^F#
16 426.666 9/7 435.084 -8.418 Augmented 3rd A3 Fx
17 453.333 13/10 454.294 -0.961 Diminished 4th d4 Gb
18 480.000 21/16 470.781 9.219 Down 4th v4 vG
19 506.666 4/3 498.045 8.622 Perfect 4th P4 G
20 533.333 49/36 533.742 -0.409 Up 4th or Mid 4th ^4, ~4 ^G
21 560.000 18/13 563.382 -3.382 Augmented 4th A4 G#
22 586.666 7/5 582.512 4.155 Upaugmented 4th ^A4 ^G#
23 613.333 10/7 617.488 -4.155 Downdiminshed 5th vd5 vAb
24 640.000 13/9 636.618 3.382 Diminished 5th d5 Ab
25 666.666 72/49 666.258 0.409 Down 5th or Mid 5th v5, ~5 vA
26 693.333 3/2 701.955 -8.622 Perfect 5th P5 A
27 720.000 32/21 729.219 -9.219 Up 5th ^5 ^A
28 746.666 20/13 745.786 0.961 Augmented 5th A5 A#
29 773.333 14/9 764.916 8.418 Diminished 6th d6 Bbb
30 800.000 100/63 799.892 0.108 Downminor 6th vm6 vBb
31 826.666 8/5 813.686 12.980 Minor 6th m6 Bb
32 853.333 18/11 852.592 0.741 Mid 6th ~6 vB
33 880.000 5/3 884.359 -4.359 Major 6th M6 B
34 906.666 27/16 905.865 0.802 Upmajor 6th ^M6 ^B
35 933.333 12/7 933.129 0.205 Augmented 6th A6 B#
36 960.000 7/4 968.826 -8.826 Diminished 7th d7 Cb
37 986.666 16/9 996.089 -9.423 Downminor 7th vm7 vC
38 1013.333 9/5 1017.596 -4.262 Minor 7th m7 C
39 1040.000 20/11 1034.996 5.004 Mid 7th ~7 ^C
40 1066.666 50/27 1066.762 -0.095 Major 7th M7 C#
41 1093.333 32/17 1095.044 -1.711 Upmajor 7th ^M7 ^C#
42 1120.000 21/11 1119.463 0.537 Augmented 7th A7 Cx
43 1146.666 64/33 1146.727 -0.060 Diminished 8ve d8 Db
44 1173.333 128/65 1173.158 0.174 Down 8ve v8 vD
45 1200.000 2/1 1200.000 0.000 Perfect Octave P8 D

Notation

Ups and Downs notation

Spoken as up, sharp, upsharp, etc. Note that up can be respelled as downsharp.

Step offset −4 −3 −2 −1 0 +1 +2 +3 +4
Symbol

Quarter-tone notation

Since a sharp raises by two steps, quarter-tone accidentals can also be used.

Step offset −4 −3 −2 −1 0 +1 +2 +3 +4
Symbol

Sagittal notation

This notation uses the same sagittal sequence as EDOs 52 and 59b.

Evo flavor

Sagittal notationPeriodic table of EDOs with sagittal notation36/351053/1024

Revo flavor

Sagittal notationPeriodic table of EDOs with sagittal notation36/351053/1024

Evo-SZ flavor

Sagittal notationPeriodic table of EDOs with sagittal notation36/351053/1024

Because it contains no Sagittal symbols, this Evo-SZ Sagittal notation is also a Stein-Zimmerman notation.

In the following diagrams, a sagittal symbol followed by an equals sign (=) means that the following comma is the symbol's primary comma (the comma it exactly represents in JI), while an approximately equals sign (≈) means it is a secondary comma (a comma it approximately represents in JI). In both cases the symbol exactly represents the tempered version of the comma in this EDO.

Regular temperament properties

Commas

This is a partial list of the commas that 45et tempers out with its patent val, 45 71 104 126 143 156 167].

Prime
limit
Ratio[note 1] Monzo Cents Color name Name(s)
5 81/80 [-4 4 -1 21.51 Gu Syntonic comma, Didymus comma, meantone comma
5 (26 digits) [1 -27 18 0.86 Satritribiyo Ennealimma
7 16807/16384 [-14 0 0 5 44.13 Laquinzo Cloudy comma
7 525/512 [-9 1 2 1 43.41 Lazoyoyo Avicennma, Avicenna's enharmonic diesis
7 875/864 [-5 -3 3 1 21.90 Zotrigu Keema
7 3125/3087 [0 -2 5 -3 21.18 Triru-aquinyo Gariboh comma
7 (16 digits) [-11 -9 0 9 1.84 Tritrizo Septimal ennealimma
7 4375/4374 [-1 -7 4 1 0.40 Zoquadyo Ragisma
11 45/44 [-2 2 1 0 -1 38.91 Luyo Undecimal 1/5-tone
11 385/384 [-7 -1 1 1 1 4.50 Lozoyo Keenanisma
11 (18 digits) [24 -6 0 1 -5 0.51 Saquinlu-azo Quartisma
  1. Ratios longer than 10 digits are presented by placeholders with informative hints.

Octave stretch and compression

45edo's approximations of 3/1, 5/1, 7/1, 11/1 and 13/1 and 17/1 are all improved by an stretched-octave version of 45edo, such as 116ed6. The trade-off is a slightly worse 2/1.

The tuning 183ed17 may be used for this purpose too, it improves 3/1, 5/1, 7/1, 11/1, 13/1 and 17/1, but at the cost of a noticeably worse 2/1 than 116ed6.

What follows is a comparison of compressed- and stretched-octave 45edo tunings.

209zpi
  • Step size: 26.550 ¢, octave size: 1194.8 ¢

Compressing the octave of 45edo by around 5 ¢ results in improved primes 5 and 7, but worse primes 2, 3, 11 and 13. This approximates all harmonics up to 16 within 11.1 ¢. The tuning 209zpi does this.

Approximation of harmonics in 209zpi
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) -5.2 +9.6 -10.5 +1.4 +4.4 +3.0 +10.8 -7.3 -3.8 -9.5 -0.9
Relative (%) -19.8 +36.3 -39.5 +5.4 +16.6 +11.4 +40.7 -27.3 -14.4 -35.8 -3.2
Step 45 72 90 105 117 127 136 143 150 156 162
Approximation of harmonics in 209zpi (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -6.7 -2.2 +11.1 +5.6 +6.8 -12.5 +0.1 -9.1 +12.7 +11.8 -12.1 -6.1
Relative (%) -25.2 -8.4 +41.7 +20.9 +25.6 -47.1 +0.3 -34.1 +47.7 +44.4 -45.5 -23.0
Step 167 172 177 181 185 188 192 195 199 202 204 207
45edo
  • Step size: 26.667 ¢, octave size: 1200.0 ¢

Pure-octaves 45edo approximates all harmonics up to 16 within 13.0 ¢.

Approximation of harmonics in 45edo
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +0.0 -8.6 +0.0 -13.0 -8.6 -8.8 +0.0 +9.4 -13.0 +8.7 -8.6
Relative (%) +0.0 -32.3 +0.0 -48.7 -32.3 -33.1 +0.0 +35.3 -48.7 +32.6 -32.3
Steps
(reduced)
45
(0)
71
(26)
90
(0)
104
(14)
116
(26)
126
(36)
135
(0)
143
(8)
149
(14)
156
(21)
161
(26)
Approximation of harmonics in 45edo (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) +12.8 -8.8 +5.1 +0.0 +1.7 +9.4 -4.2 -13.0 +9.2 +8.7 +11.7 -8.6
Relative (%) +48.0 -33.1 +19.0 +0.0 +6.4 +35.3 -15.7 -48.7 +34.6 +32.6 +44.0 -32.3
Steps
(reduced)
167
(32)
171
(36)
176
(41)
180
(0)
184
(4)
188
(8)
191
(11)
194
(14)
198
(18)
201
(21)
204
(24)
206
(26)
45et, 13-limit WE tuning
  • Step size: 26.695 ¢, octave size: 1201.3 ¢

Stretching the octave of 45edo by around 1 ¢ results in improved primes 3, 5, 7 and 13, but worse primes 2 and 11. This approximates all harmonics up to 16 within 13.2 ¢. Its 13-limit WE tuning and 13-limit TE tuning both do this.

Approximation of harmonics in 45et, 13-limit WE tuning
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +1.3 -6.6 +2.5 -10.0 -5.3 -5.3 +3.8 -13.2 -8.8 +13.1 -4.1
Relative (%) +4.8 -24.8 +9.6 -37.6 -20.0 -19.7 +14.3 -49.5 -32.8 +49.1 -15.2
Step 45 71 90 104 116 126 135 142 149 156 161
Approximation of harmonics in 45et, 13-limit WE tuning (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -9.2 -4.0 +10.1 +5.1 +6.9 -11.9 +1.2 -7.5 -11.9 -12.3 -9.2 -2.8
Relative (%) -34.3 -14.9 +37.7 +19.1 +25.9 -44.7 +4.6 -28.0 -44.4 -46.1 -34.4 -10.4
Step 166 171 176 180 184 187 191 194 197 200 203 206
161ed12
  • Step size: Octave size: 1202.4 ¢

Stretching the octave of 45edo by around 2.5 ¢ results in improved primes 3, 5, 7 and 13, but worse primes 2 and 11. This approximates all harmonics up to 16 within 12.2 ¢. The tuning 161ed12 does this.

Approximation of harmonics in 161ed12
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +2.4 -4.8 +4.8 -7.4 -2.4 -2.1 +7.2 -9.6 -5.0 -9.7 +0.0
Relative (%) +9.0 -18.0 +18.0 -27.7 -9.0 -7.8 +27.1 -36.1 -18.7 -36.2 +0.0
Steps
(reduced)
45
(45)
71
(71)
90
(90)
104
(104)
116
(116)
126
(126)
135
(135)
142
(142)
149
(149)
155
(155)
161
(0)
Approximation of harmonics in 161ed12 (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -5.0 +0.3 -12.2 +9.6 +11.6 -7.2 +6.0 -2.6 -6.9 -7.3 -4.1 +2.4
Relative (%) -18.6 +1.2 -45.8 +36.1 +43.3 -27.1 +22.6 -9.7 -25.8 -27.2 -15.2 +9.0
Steps
(reduced)
166
(5)
171
(10)
175
(14)
180
(19)
184
(23)
187
(26)
191
(30)
194
(33)
197
(36)
200
(39)
203
(42)
206
(45)
116ed6
  • Step size: Octave size: 1203.3 ¢

Stretching the octave of 45edo by around 3 ¢ results in improved primes 3, 5, 7, 11 and 13, but a worse prime 2. This approximates all harmonics up to 16 within 13.4 ¢. The tuning 116ed6 does this. So does 126ed7 whose octave is identical within 0.1 ¢.

Approximation of harmonics in 116ed6
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +3.3 -3.3 +6.7 -5.3 +0.0 +0.5 +10.0 -6.7 -1.9 -6.5 +3.3
Relative (%) +12.5 -12.5 +25.0 -19.6 +0.0 +2.0 +37.5 -25.0 -7.1 -24.2 +12.5
Steps
(reduced)
45
(45)
71
(71)
90
(90)
104
(104)
116
(0)
126
(10)
135
(19)
142
(26)
149
(33)
155
(39)
161
(45)
Approximation of harmonics in 116ed6 (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -1.5 +3.9 -8.6 -13.4 -11.4 -3.3 +10.0 +1.4 -2.8 -3.1 +0.1 +6.7
Relative (%) -5.7 +14.5 -32.1 -50.0 -42.5 -12.5 +37.5 +5.4 -10.5 -11.7 +0.5 +25.0
Steps
(reduced)
166
(50)
171
(55)
175
(59)
179
(63)
183
(67)
187
(71)
191
(75)
194
(78)
197
(81)
200
(84)
203
(87)
206
(90)
45et, 7-limit WE tuning
  • Step size: 26.745 ¢, octave size: 1203.5 ¢

Stretching the octave of 45edo by around 3.5 ¢ results in improved primes 3, 5, 7, 11 and 13, but a worse prime 2. This approximates all harmonics up to 16 within 12.6 ¢. Its 7-limit WE tuning and 7-limit TE tuning both do this.

Approximation of harmonics in 45et, 7-limit WE tuning
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +3.5 -3.1 +7.1 -4.8 +0.5 +1.0 +10.6 -6.1 -1.3 -5.8 +4.0
Relative (%) +13.2 -11.4 +26.4 -18.1 +1.7 +3.9 +39.5 -22.9 -4.9 -21.8 +14.9
Step 45 71 90 104 116 126 135 142 149 155 161
Approximation of harmonics in 45et, 7-limit WE tuning (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) -0.9 +4.6 -7.9 -12.6 -10.6 -2.6 +10.8 +2.2 -2.0 -2.3 +1.0 +7.5
Relative (%) -3.2 +17.1 -29.5 -47.3 -39.7 -9.7 +40.3 +8.3 -7.5 -8.7 +3.6 +28.1
Step 166 171 175 179 183 187 191 194 197 200 203 206
207zpi
  • Step size: 26.762 ¢, octave size: 1204.3 ¢

Stretching the octave of 45edo by around 4 ¢ results in improved primes 3, 5, 7, 11 and 13, but a worse prime 2. This approximates all harmonics up to 16 within 12.9 ¢. The tuning 207zpi does this.

Approximation of harmonics in 207zpi
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +4.3 -1.9 +8.6 -3.1 +2.4 +3.2 +12.9 -3.7 +1.2 -3.2 +6.7
Relative (%) +16.0 -6.9 +32.1 -11.5 +9.1 +11.9 +48.1 -13.8 +4.6 -12.0 +25.1
Step 45 71 90 104 116 126 135 142 149 155 161
Approximation of harmonics in 207zpi (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) +2.0 +7.5 -4.9 -9.6 -7.5 +0.6 -12.7 +5.5 +1.3 +1.1 +4.4 +11.0
Relative (%) +7.3 +27.9 -18.4 -35.9 -28.1 +2.2 -47.6 +20.6 +5.0 +4.0 +16.5 +41.2
Step 166 171 175 179 183 187 190 194 197 200 203 206
71edt
  • Step size: 26.788 ¢, octave size: 1205.5 ¢

Stretching the octave of 45edo by around 5.5 ¢ results in improved primes 3, 5, 7, 11 and 13, but a worse prime 2. This approximates all harmonics up to 16 within 11.9 ¢. The tuning 71edt does this. So do the tunings 104ed5 and 155ed11 whose octave is identical within 0.3 ¢.

Approximation of harmonics in 71edt
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +5.5 +0.0 +10.9 -0.4 +5.5 +6.5 -10.4 +0.0 +5.1 +0.8 +10.9
Relative (%) +20.4 +0.0 +40.8 -1.3 +20.4 +24.2 -38.8 +0.0 +19.1 +3.1 +40.8
Steps
(reduced)
45
(45)
71
(0)
90
(19)
104
(33)
116
(45)
126
(55)
134
(63)
142
(0)
149
(7)
155
(13)
161
(19)
Approximation of harmonics in 71edt (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) +6.3 +11.9 -0.4 -4.9 -2.7 +5.5 -7.8 +10.6 +6.5 +6.3 +9.7 -10.4
Relative (%) +23.5 +44.6 -1.3 -18.4 -10.2 +20.4 -29.0 +39.5 +24.2 +23.5 +36.2 -38.8
Steps
(reduced)
166
(24)
171
(29)
175
(33)
179
(37)
183
(41)
187
(45)
190
(48)
194
(52)
197
(55)
200
(58)
203
(61)
205
(63)
183ed17
  • Octave size: 1206.1 ¢

Stretching the octave of 45edo by around 6 ¢ results in improved primes 3, 5, 7, 11, 13 and 17, but a worse prime 2. This approximates all harmonics up to 16 within 13.3 ¢. The tuning 183ed17 does this.

Approximation of harmonics in 183ed17
Harmonic 2 3 4 5 6 7 8 9 10 11 12
Error Absolute (¢) +6.1 +1.1 +12.3 +1.2 +7.2 +8.4 -8.4 +2.1 +7.3 +3.2 +13.3
Relative (%) +22.9 +4.0 +45.8 +4.5 +26.9 +31.2 -31.3 +7.9 +27.4 +11.8 +49.7
Steps
(reduced)
45
(45)
71
(71)
90
(90)
104
(104)
116
(116)
126
(126)
134
(134)
142
(142)
149
(149)
155
(155)
161
(161)
Approximation of harmonics in 183ed17 (continued)
Harmonic 13 14 15 16 17 18 19 20 21 22 23 24
Error Absolute (¢) +8.8 -12.3 +2.3 -2.3 +0.0 +8.3 -4.9 -13.3 +9.4 +9.3 +12.7 -7.3
Relative (%) +32.7 -45.9 +8.4 -8.4 +0.0 +30.8 -18.4 -49.7 +35.1 +34.7 +47.5 -27.4
Steps
(reduced)
166
(166)
170
(170)
175
(175)
179
(179)
183
(0)
187
(4)
190
(7)
193
(10)
197
(14)
200
(17)
203
(20)
205
(22)

Instruments

Lumatone

See Lumatone mapping for 45edo

Music

Bryan Deister
JUMBLE