1216/1215: Difference between revisions
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'''1216/1215''', the '''password''' or '''Eratosthenes' comma''', is a [[19-limit]] (also 2.3.5.19 subgroup) unnoticeable comma. It is the amount by which [[19/15]] exceeds the [[81/64|Pythagorean major third (81/64)]], or [[20/19]] falls short of the [[256/243|Pythagorean minor second (256/243)]]. It is also the difference between [[19/18]], the undevicesimal semitone and [[135/128]], the major chroma, and in addition, between the [[256/255|septendecimal kleisma]] and the [[324/323|nusu comma]], between the [[361/360|go comma]] and the [[513/512|undevicesimal comma]], and between the undevicesimal comma and the [[schisma]]. | '''1216/1215''', the '''password''' or '''Eratosthenes' comma''', is a [[19-limit]] (also 2.3.5.19 subgroup) unnoticeable comma. It is the amount by which [[19/15]] exceeds the [[81/64|Pythagorean major third (81/64)]], or [[20/19]] falls short of the [[256/243|Pythagorean minor second (256/243)]]. It is also the difference between [[19/18]], the undevicesimal semitone and [[135/128]], the major chroma, and in addition, between the [[256/255|septendecimal kleisma]] and the [[324/323|nusu comma]], between the [[361/360|go comma]] and the [[513/512|undevicesimal comma]], and between the undevicesimal comma and the [[schisma]]. | ||
By tempering it out is defined the '''eratosthenes temperament''', which enables the | By tempering it out is defined the '''eratosthenes temperament''', which enables the [[eratosthenes chords]]. EDOs supporting this temperament includes {{Optimal ET sequence| 12, 29, 41, 53, 65, 77, 87, 94, 99, 106, 111, 118, 130, 140, 152, 159, 183, 193, 205, 217, 270, 282, 311, 323, 364, 400, 422, 581, and 692}}. | ||
== See also == | == See also == | ||
Revision as of 15:14, 20 July 2023
| Interval information |
Eratosthenes' comma
Sanogu comma
reduced
1216/1215, the password or Eratosthenes' comma, is a 19-limit (also 2.3.5.19 subgroup) unnoticeable comma. It is the amount by which 19/15 exceeds the Pythagorean major third (81/64), or 20/19 falls short of the Pythagorean minor second (256/243). It is also the difference between 19/18, the undevicesimal semitone and 135/128, the major chroma, and in addition, between the septendecimal kleisma and the nusu comma, between the go comma and the undevicesimal comma, and between the undevicesimal comma and the schisma.
By tempering it out is defined the eratosthenes temperament, which enables the eratosthenes chords. EDOs supporting this temperament includes 12, 29, 41, 53, 65, 77, 87, 94, 99, 106, 111, 118, 130, 140, 152, 159, 183, 193, 205, 217, 270, 282, 311, 323, 364, 400, 422, 581, and 692.