Logarithmic phi: Difference between revisions

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| Name = logarithmic phi
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'''Logarithmic phi''', or 1200*[[Phi|<math>\varphi</math>]] cents = 1941.6 cents (or, octave-reduced, 741.6 cents) is useful as a generator, for example in [[Erv Wilson]]'s "Golden Horagrams". As a frequency relation it is <math>2^{\varphi}</math>, or <math>2^{\varphi - 1} = 2^{1/\varphi}</math> when octave-reduced. Logarithmic phi is notable for being the most difficult interval to approximate by [[EDO]]s, and as such a "small equal division of logarithmic phi" [[nonoctave]] tuning would minimize pseudo-octaves.
'''Logarithmic phi''', or [[phi|<math>\varphi</math>]] [[2/1|octave]]s = 1941.6 [[cent]]s (or, octave-reduced, 741.6 cents) is useful as a generator, for example in [[Erv Wilson]]'s "Golden Horagrams". As a frequency relation it is <math>2^{\varphi}</math>, or <math>2^{\varphi - 1} = 2^{1/\varphi}</math> when octave-reduced. Logarithmic phi is notable for being the most difficult interval to approximate by [[edo]]s, and as such a "small equal division of logarithmic phi" [[nonoctave]] tuning would minimize pseudo-octaves.
   
   
Logarithmic phi is not to be confused with [[acoustic phi]], which is 833..
Logarithmic phi is not to be confused with [[acoustic phi]], which is 833.1{{c}}.


==See also==
Logarithmic phi is well-approximated in equal divisions of the octave corresponding to the Fibonacci sequence: [[8edo]], [[13edo]], [[21edo]], [[34edo]], [[55edo]], etc.
 
== See also ==
* [[Generating a scale through successive divisions of the octave by the Golden Ratio]]
* [[Generating a scale through successive divisions of the octave by the Golden Ratio]]
* [[Golden sequences and tuning]]
* [[Golden sequences and tuning]]
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* [[Metallic MOS]]
* [[Metallic MOS]]


;The MOS patterns generated by logarithmic phi
; The MOS patterns generated by logarithmic phi
* [[3L 2s]]
* [[3L 2s]]
* [[5L 3s]]
* [[5L 3s]]
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* [[13L 8s]]
* [[13L 8s]]
* [[21L 13s]]
* [[21L 13s]]
* ...
*


;Related regular temperaments
; Related regular temperaments
*[[Father family|Father temperament]]
* [[Father family|Father temperament]]
*[[Keegic temperaments #Aurora|Aurora temperament]]
* [[Keegic temperaments #Aurora|Aurora temperament]]
*[[Triforce]] divides an 1/3 octave period into logarithmic-phi-sized fractions.
* [[Triforce]] divides an 1/3 octave period into logarithmic-phi-sized fractions.


;Music
; Music
*[http://www.elvenminstrel.com/music/tuning/horagrams/horagram_intro.htm 5- to 9-tone, octave-repeating scales from Wilson's Golden Horagrams of the Scale Tree], by [[David Finnamore]]
* [http://www.elvenminstrel.com/music/tuning/horagrams/horagram_intro.htm 5- to 9-tone, octave-repeating scales from Wilson's Golden Horagrams of the Scale Tree], by [[David Finnamore]]


[[Category:Golden ratio]]
[[Category:Golden ratio]]