Tenney norm: Difference between revisions

Cmloegcmluin (talk | contribs)
m prefer "log-product" to "log product"
m - Wikipedia link. There's an article for James Tenney
 
(16 intermediate revisions by 5 users not shown)
Line 1: Line 1:
{{Wikipedia| James Tenney }}
{{Texops}}
 
The '''Tenney norm''', otherwise known as '''harmonic distance''' ('''HD''') or '''Tenney height''', is commonly used as a measure of [[complexity]] for [[just interval]]s. If ''n''/''d'' is a positive rational number reduced to its lowest terms, then the [[Benedetti height]] is the integer ''nd''. Often it is more convenient instead to take the logarithm, usually base 2 ([[log2]]), of the Benedetti height, leading to the Tenney norm.  
If ''n''/''d'' is a positive rational number reduced to its lowest terms, then the [[Benedetti height]] is the integer ''nd''. Often it is more convenient instead to take the logarithm, usually base 2 ([[log2]]), of the [[Benedetti height]], leading to '''Tenney height'''. In either form, it is widely used as a [[measure of inharmonicity]] and/or complexity for intervals. Alternative terms used include '''harmonic distance''' ('''HD''').
 
== Names ==
In general mathematics, this measurement is known as ''log-product complexity''. With respect to microtonal tuning, this measurement was first described by [[James Tenney]], who himself called it ''harmonic distance''.<ref>[https://www.plainsound.org/pdfs/JC&ToH.pdf ''John Cage and the Theory of Harmony'']. James Tenney. </ref><ref>[https://zh.booksc.eu/book/68954431/f87a1d ''On the Conception and Measure of Consonance'']. Alex Wand. </ref><ref>[https://scholar.sun.ac.za/bitstream/handle/10019.1/98644/brand_signal_2016.pdf?sequence=2&isAllowed=y ''A Signal-Based Model of Teleology in Tonal Music'']. Mark André Brand. p. 28. "Tenney's measure of ''harmonic distance'' (Hd) is thus singled out as perhaps his most 'crucial development', affording him the means towards 'compactness'. His is a Manhattan, rather than Euclidean metric, defined as Hd (''a''/''b'') = ''k''log(''ab''), with ''a''/''b'' the maximally reduced ratio representing the frequency difference, and ''k'' = 1 indicating measure in octaves."</ref> This terminology was also used in [[Paul Erlich]]'s paper [[A Middle Path]]<ref>Wherein Erlich writes: "This is why, in Tenney’s terminology, the taxicab distance an interval traverses in his lattice is the 'Harmonic Distance' of that interval."</ref>. 


== Computation ==
== Computation ==
=== Ratio form ===
=== Ratio form ===
The Tenney height of a ratio ''n''/''d'' is given by
The Tenney norm of a ratio ''n''/''d'' is given by


<math>\log_2 (nd)</math>
$$\log_2 (nd) $$


=== Vector form ===
=== Vector form ===
The Tenney height of a [[Harmonic limit|''p''-limit]] [[monzo]] b = {{monzo| ''b''<sub>1</sub> ''b''<sub>2</sub> … ''b''<sub>π (''p'')</sub> }} (π being the [[Wikipedia: prime-counting function|prime-counting function]]) is given by
The Tenney norm of a [[harmonic limit|''p''-limit]] [[monzo]] {{nowrap|'''m''' {{=}} {{monzo| ''m''<sub>1</sub> ''m''<sub>2</sub> … ''m''<sub>π (''p'')</sub> }}}} (π being the {{w|prime-counting function}}) is given by


<math>\lVert H \vec b \rVert_1 \\
$$
= \vert b_1 \vert + \vert b_2 \vert \log_2 (3) + \ldots + \vert b_{\pi (p)} \vert \log_2 (p) \\
\begin{align}
= \log_2 (2^{|b_1|} \cdot 3^{|b_2|} \cdot \ldots \cdot p^{|b_{\pi (p)}|})</math>
\norm{H \vec m}_1 &= \abs{m_1} + \abs{m_2} \log_2 (3) + \ldots + \abs{m_{\pi (p)}} \log_2 (p) \\
&= \log_2\left(2^{\abs{m_1}} \cdot 3^{\abs{m_2}} \cdot \ldots \cdot p^{\abs{m_{\pi (p)}}}\right)
\end{align}
$$


where H is the transformation matrix such that, for the prime basis Q = {{val| 2 3 5 … ''p'' }},  
where ''H'' is the transformation matrix such that, for the prime basis {{nowrap| ''Q'' {{=}} {{val| 2 3 5 … ''p'' }} }},  


<math>H = \operatorname {diag} (\log_2 (Q))</math>
$$ H = \operatorname {diag} (\log_2 (Q)) $$


== Examples ==
== Examples ==
{| class="wikitable"
{| class="wikitable center-2"
|-
! Interval name
! Interval name
! Ratio (''n''/''d'')
! Ratio (''n''/''d'')
! Monzo
! Monzo
! Tenney height
! Tenney norm
|-
|-
| Unison
| Unison
Line 55: Line 55:
| 4.807
| 4.807
|}
|}
== History and terminology ==
In general mathematics, this measurement is known as ''log-product complexity''. With respect to microtonal tuning, this measurement was first described by [[James Tenney]], who himself called it ''harmonic distance''.<ref>[https://www.plainsound.org/pdfs/JC&ToH.pdf ''John Cage and the Theory of Harmony'']. James Tenney. </ref><ref>[https://zh.booksc.eu/book/68954431/f87a1d ''On the Conception and Measure of Consonance'']. Alex Wand. </ref><ref>[https://scholar.sun.ac.za/bitstream/handle/10019.1/98644/brand_signal_2016.pdf?sequence=2&isAllowed=y ''A Signal-Based Model of Teleology in Tonal Music'']. Mark André Brand. p. 28. "Tenney's measure of ''harmonic distance'' (Hd) is thus singled out as perhaps his most 'crucial development', affording him the means towards 'compactness'. His is a Manhattan, rather than Euclidean metric, defined as {{nowrap|Hd(''a''/''b'') {{=}} ''k'' log(''ab'')}}, with ''a''/''b'' the maximally reduced ratio representing the frequency difference, and {{nowrap|''k'' {{=}} 1}} indicating measure in octaves."</ref> This terminology was also used in [[Paul Erlich]]'s paper [[A Middle Path]]<ref>Wherein Erlich writes: "This is why, in Tenney’s terminology, the taxicab distance an interval traverses in his lattice is the 'Harmonic Distance' of that interval."</ref>. 


== See also ==
== See also ==
* [[Generalized Tenney norms and Tp interval space|Generalized Tenney norms and T<sub>''p''</sub> interval space]]


* [[Generalized Tenney Norms and Tp Interval Space]]
== References ==
 
<references />
== Notes ==


[[Category:Regular temperament theory]]
[[Category:Consonance and dissonance]]
[[Category:Psychoacoustics]]
[[Category:Harmonic entropy]]
[[Category:Harmonic entropy]]
[[Category:Tenney]]
[[Category:Interval complexity measures]]
[[Category:Benedetti]]
[[Category:Tenney-weighted measures]]
[[Category:Consonance]]
[[Category:Dissonance]]
[[Category:Height]]
[[Category:Measure]]