Logarithmic phi: Difference between revisions

From Xenharmonic Wiki
Jump to navigation Jump to search
Cmloegcmluin (talk | contribs)
extracting info from main phi page which was only relevant to logarithmic phi
deleted the mmtm theory link
Line 4: Line 4:
| Name = logarithmic phi
| Name = logarithmic phi
}}
}}
'''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. With or without pseudo-octaves, an "equal division of logarithmic phi" [[nonoctave]] tuning forms an [[Modal systematization of soid-family scales| Intense Phrygian-Subpental Aeolian]] mode.
'''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 is not to be confused with [[acoustic phi]], which is 833.1¢.
Logarithmic phi is not to be confused with [[acoustic phi]], which is 833.1¢.

Revision as of 15:34, 28 March 2025

Interval information
Expression [math]\displaystyle{ 2^{\varphi} = 2^{\frac{1+\sqrt{5} } {2} } }[/math]
Size in cents 1941.641¢
Name logarithmic phi

Logarithmic phi, or 1200*[math]\displaystyle{ \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]\displaystyle{ 2^{\varphi} }[/math], or [math]\displaystyle{ 2^{\varphi - 1} = 2^{1/\varphi} }[/math] when octave-reduced. Logarithmic phi is notable for being the most difficult interval to approximate by EDOs, 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 833.1¢.

See also

The MOS patterns generated by logarithmic phi
Related regular temperaments
Music