677edo: Difference between revisions
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{{Infobox ET}} | {{Infobox ET}} | ||
{{ | {{ED intro}} | ||
== Theory == | == Theory == | ||
While it does well as a 2.3.5.11 tuning system, it's notable for its high accuracy among EDOs of about its size and lower with the first several [[wikipedia:Metallic_mean|metallic ratios]]. Among those, it tunes [[acoustic phi]] (the golden ratio) and the acoustic copper ratio each with less than 1% relative error. The first nine metallic ratios are all tuned within 20% of an edostep. | While it does well as a 2.3.5.11 tuning system, it's notable for its high accuracy among EDOs of about its size and lower with the first several [[wikipedia:Metallic_mean|metallic ratios]]. Among those, it tunes [[acoustic phi]] (the golden ratio) and the acoustic copper ratio each with less than 1% relative error. The first nine metallic ratios are all tuned within 20% of an edostep. | ||
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== Regular temperament properties == | == Regular temperament properties == | ||
{| class="wikitable center-4 center-5 center-6" | {| class="wikitable center-4 center-5 center-6" | ||
|- | |- | ||
|2.3 | ! rowspan="2" | [[Subgroup]] | ||
|{{monzo|-1073 677}} | ! rowspan="2" | [[Comma list]] | ||
|{{mapping|677 1073}} | ! rowspan="2" | [[Mapping]] | ||
! rowspan="2" | Optimal<br />8ve stretch (¢) | |||
! colspan="2" | Tuning error | |||
|- | |||
! [[TE error|Absolute]] (¢) | |||
! [[TE simple badness|Relative]] (%) | |||
|- | |||
| 2.3 | |||
| {{monzo|-1073 677}} | |||
| {{mapping|677 1073}} | |||
| +0.0110 | | +0.0110 | ||
| 0.0110 | | 0.0110 | ||
| 0.62 | | 0.62 | ||
|- | |- | ||
|2.3.5 | | 2.3.5 | ||
|{{monzo|38 -2 -15}}, {{monzo|-31 43 -16}} | | {{monzo|38 -2 -15}}, {{monzo|-31 43 -16}} | ||
|{{mapping|677 1073 1572}} | | {{mapping|677 1073 1572}} | ||
| | | −0.0066 | ||
| 0.0264 | | 0.0264 | ||
| 1.49 | | 1.49 | ||
|- | |- | ||
|2.3.5.7 | | 2.3.5.7 | ||
|703125/702464, 589824/588245, 14348907/14336000 | | 703125/702464, 589824/588245, 14348907/14336000 | ||
|{{mapping|677 1073 1572 1901}} | | {{mapping|677 1073 1572 1901}} | ||
| | | −0.0714 | ||
| 0.1145 | | 0.1145 | ||
| 6.46 | | 6.46 | ||
|- | |- | ||
|2.3.5.7.11 | | 2.3.5.7.11 | ||
|3025/3024, 24057/24010, 131072/130977, 759375/758912 | | 3025/3024, 24057/24010, 131072/130977, 759375/758912 | ||
|{{mapping|677 1073 1572 1901 2342}} | | {{mapping|677 1073 1572 1901 2342}} | ||
| | | −0.0535 | ||
| 0.1084 | | 0.1084 | ||
| 6.12 | | 6.12 | ||
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=== Rank-2 temperaments === | === Rank-2 temperaments === | ||
{| class="wikitable center-all left-5" | {| class="wikitable center-all left-5" | ||
|+Table of rank-2 temperaments by generator | |+ style="font-size: 105%;" | Table of rank-2 temperaments by generator | ||
! Periods<br>per 8ve | |- | ||
! Generator | ! Periods<br />per 8ve | ||
! Cents | ! Generator* | ||
! Associated<br> | ! Cents* | ||
! Associated<br />ratio* | |||
! Temperaments | ! Temperaments | ||
|- | |- | ||
|1 | | 1 | ||
|109\677 | | 109\677 | ||
|193.21 | | 193.21 | ||
|262144/234375 | | 262144/234375 | ||
|[[Luna]] | | [[Luna]] | ||
|- | |- | ||
|1 | | 1 | ||
|125\677 | | 125\677 | ||
|221.57 | | 221.57 | ||
|8388608/7381125 | | 8388608/7381125 | ||
|[[Fortune]] | | [[Fortune]] | ||
|- | |- | ||
|1 | | 1 | ||
|281\677 | | 281\677 | ||
|498.08 | | 498.08 | ||
|4/3 | | 4/3 | ||
|[[Counterschismic]] | | [[Counterschismic]] | ||
|} | |} | ||
<nowiki />* [[Normal lists|Octave-reduced form]], reduced to the first half-octave, and [[Normal lists|minimal form]] in parentheses if distinct | |||
== Music == | |||
; [[Francium]] | |||
* "From the Ears of the Eel" from ''Scoop'' (2024) – [https://open.spotify.com/track/163kPfkX9BJ6l7jXbJDVOG Spotify] | [https://francium223.bandcamp.com/track/from-the-ears-of-the-eel Bandcamp] | [https://www.youtube.com/watch?v=WHY3EKLi7Zk YouTube] | |||
* "The Scallop Disco Accident" from ''The Scallop Disco Accident'' (2025) – [https://open.spotify.com/track/3C4sVxcVJWIZqgbpgxoQo1 Spotify] | [https://francium223.bandcamp.com/track/the-scallop-disco-accident Bandcamp] | [https://www.youtube.com/watch?v=V12N5jC_UfM YouTube] | |||
* "Make Gecko Expansion" from ''I Want To'' (2025) – [https://open.spotify.com/track/5dbEP5zQQrrO00f3XZiELV Spotify] | [https://francium223.bandcamp.com/track/make-gecko-expansion Bandcamp] | [https://www.youtube.com/watch?v=D55Y0-p_mWU YouTube] | |||
* "Eggs Of An Oven" from ''Eggs'' (2025) – [https://open.spotify.com/track/0pe7FES4PhYa58UBaQScAS Spotify] | [https://francium223.bandcamp.com/track/eggs-of-an-oven Bandcamp] | [https://www.youtube.com/watch?v=sejOxKdHd8E YouTube] |
Latest revision as of 11:54, 28 April 2025
← 676edo | 677edo | 678edo → |
677 equal divisions of the octave (abbreviated 677edo or 677ed2), also called 677-tone equal temperament (677tet) or 677 equal temperament (677et) when viewed under a regular temperament perspective, is the tuning system that divides the octave into 677 equal parts of about 1.77 ¢ each. Each step represents a frequency ratio of 21/677, or the 677th root of 2.
Theory
While it does well as a 2.3.5.11 tuning system, it's notable for its high accuracy among EDOs of about its size and lower with the first several metallic ratios. Among those, it tunes acoustic phi (the golden ratio) and the acoustic copper ratio each with less than 1% relative error. The first nine metallic ratios are all tuned within 20% of an edostep.
Prime harmonics
Harmonic | 2 | 3 | 5 | 7 | 11 | 13 | 17 | 19 | 23 | |
---|---|---|---|---|---|---|---|---|---|---|
Error | Absolute (¢) | +0.00 | -0.03 | +0.10 | +0.75 | -0.06 | -0.35 | -0.38 | +0.27 | -0.80 |
Relative (%) | +0.0 | -2.0 | +5.5 | +42.1 | -3.5 | -19.8 | -21.2 | +15.3 | -45.1 | |
Steps (reduced) |
677 (0) |
1073 (396) |
1572 (218) |
1901 (547) |
2342 (311) |
2505 (474) |
2767 (59) |
2876 (168) |
3062 (354) |
Subsets and supersets
677edo is the 123rd prime EDO.
Regular temperament properties
Subgroup | Comma list | Mapping | Optimal 8ve stretch (¢) |
Tuning error | |
---|---|---|---|---|---|
Absolute (¢) | Relative (%) | ||||
2.3 | [-1073 677⟩ | [⟨677 1073]] | +0.0110 | 0.0110 | 0.62 |
2.3.5 | [38 -2 -15⟩, [-31 43 -16⟩ | [⟨677 1073 1572]] | −0.0066 | 0.0264 | 1.49 |
2.3.5.7 | 703125/702464, 589824/588245, 14348907/14336000 | [⟨677 1073 1572 1901]] | −0.0714 | 0.1145 | 6.46 |
2.3.5.7.11 | 3025/3024, 24057/24010, 131072/130977, 759375/758912 | [⟨677 1073 1572 1901 2342]] | −0.0535 | 0.1084 | 6.12 |
Rank-2 temperaments
Periods per 8ve |
Generator* | Cents* | Associated ratio* |
Temperaments |
---|---|---|---|---|
1 | 109\677 | 193.21 | 262144/234375 | Luna |
1 | 125\677 | 221.57 | 8388608/7381125 | Fortune |
1 | 281\677 | 498.08 | 4/3 | Counterschismic |
* Octave-reduced form, reduced to the first half-octave, and minimal form in parentheses if distinct
Music
- "From the Ears of the Eel" from Scoop (2024) – Spotify | Bandcamp | YouTube
- "The Scallop Disco Accident" from The Scallop Disco Accident (2025) – Spotify | Bandcamp | YouTube
- "Make Gecko Expansion" from I Want To (2025) – Spotify | Bandcamp | YouTube
- "Eggs Of An Oven" from Eggs (2025) – Spotify | Bandcamp | YouTube