Octave (interval region): Difference between revisions

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The '''octave''' is one of the most basic [[Gallery of Just Intervals|intervals]] found in musical systems throughout the entire world. It is usually called the "interval of equivalence" because tones separated by an octave are perceived to have the same or similar pitch class to the average human listener. The reason for this phenomenon is probably due to the strong region of attraction of low [[Harmonic Entropy|harmonic entropy]], or the strong amplitude of the second [[harmonic]] in most harmonic instruments.
The '''octave''' (interval ratio '''2/1''') is one of the most basic [[Gallery of Just Intervals|intervals]] found in musical systems throughout the entire world. It is usually called the "interval of equivalence" because tones separated by an octave are perceived to have the same or similar pitch class to the average human listener. The reason for this phenomenon is probably due to the strong region of attraction of low [[Harmonic Entropy|harmonic entropy]], or the strong amplitude of the second [[harmonic]] in most harmonic instruments.


It has a frequency ratio of 2/1 and a size of 1200 [[cent|cents]]. It is used as the standard of (logarithmic) measurement for all intervals, regardless if they are justly tuned or not.
It has a frequency ratio of 2/1 and a size of 1200 [[cent]]s. It is used as the standard of (logarithmic) measurement for all intervals, regardless if they are justly tuned or not.


Strangely enough, the Pelog and Slendro scales of the Javanese contain near-octaves even though Gamelan instruments exhibit inharmonic spectra. It is most likely reminiscent of an older musical system, or derived using the human voice instead of inharmonic instruments.
Strangely enough, the Pelog and Slendro scales of the Javanese contain near-octaves even though Gamelan instruments exhibit inharmonic spectra. It is most likely reminiscent of an older musical system, or derived using the human voice instead of inharmonic instruments.
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* [[Ditave]] - an alternative more neutral name
* [[Ditave]] - an alternative more neutral name


[[Category:interval]]
[[Category:Interval]]

Revision as of 10:19, 25 October 2018

Interval information
Ratio 2/1
Factorization 2
Monzo [1
Size in cents 1200¢
Name octave
Color name w8, wa 8ve
FJS name [math]\displaystyle{ \text{P8} }[/math]
Special properties superparticular,
harmonic,
prime harmonic,
highly composite harmonic
Tenney norm (log2 nd) 1
Weil norm (log2 max(n, d)) 2
Wilson norm (sopfr(nd)) 2

[sound info]
Open this interval in xen-calc

The octave (interval ratio 2/1) is one of the most basic intervals found in musical systems throughout the entire world. It is usually called the "interval of equivalence" because tones separated by an octave are perceived to have the same or similar pitch class to the average human listener. The reason for this phenomenon is probably due to the strong region of attraction of low harmonic entropy, or the strong amplitude of the second harmonic in most harmonic instruments.

It has a frequency ratio of 2/1 and a size of 1200 cents. It is used as the standard of (logarithmic) measurement for all intervals, regardless if they are justly tuned or not.

Strangely enough, the Pelog and Slendro scales of the Javanese contain near-octaves even though Gamelan instruments exhibit inharmonic spectra. It is most likely reminiscent of an older musical system, or derived using the human voice instead of inharmonic instruments.

Links

See also