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== Octave equivalence == | == Octave equivalence == | ||
The octave is usually called the '''interval of equivalence''', because tones separated by | The octave is usually called the '''interval of equivalence''', because tones separated by this interval are perceived as having the same "pitch class" despite their different absolute pitches. This equivalence is so strong that in most musical notation systems, notes separated by octaves share the same name. | ||
The | The perception of octave equivalence appears to have both biological and cultural components. | ||
Studies have shown that various non-human animals, including rhesus monkeys and rats, experience octave equivalence to a certain extent.<ref>Hoeschele M. [https://doi.org/10.3819/CCBR.2017.120002 ''Animal Pitch Perception: Melodies and Harmonies'']. Comp Cogn Behav Rev. 2017</ref> | |||
However, the degree of octave equivalence perception varies across cultures, particularly in those with non-Western musical traditions.<ref>Jacoby, Nori et al. [https://doi.org/10.17605/OSF.IO/DW39V ''Universal and Non-universal Features of Musical Pitch Perception Revealed by Singing'']. Current Biology, 2019.</ref> | |||
When a different interval (such as the [[tritave]]) is used as the interval of equivalence, it is referred to as an [[equave]] or sometimes formal octave. | |||
== Octave stretch == | |||
{{main|Stretched and compressed tuning}} | |||
Some musical systems exhibit stretched (or compressed) octaves where the octave is tuned slightly different from a pure 2:1 ratio. This occurs in piano tuning (to compensate for inharmonicity in piano strings) and in some traditional music systems, such as the Indonesian [[Pelog]] and [[Slendro]] scales. | |||
== Alternative names == | == Alternative names == | ||
Revision as of 21:53, 23 April 2025
| Interval information |
ditave,
duple,
diapason
harmonic,
prime harmonic,
highly composite harmonic
[sound info]
The octave (abbreviation: 8ve, symbol: oct, frequency ratio: 2/1) is one of the most basic intervals found in musical systems throughout the entire world. 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.
Octave equivalence
The octave is usually called the interval of equivalence, because tones separated by this interval are perceived as having the same "pitch class" despite their different absolute pitches. This equivalence is so strong that in most musical notation systems, notes separated by octaves share the same name.
The perception of octave equivalence appears to have both biological and cultural components. Studies have shown that various non-human animals, including rhesus monkeys and rats, experience octave equivalence to a certain extent.[1] However, the degree of octave equivalence perception varies across cultures, particularly in those with non-Western musical traditions.[2]
When a different interval (such as the tritave) is used as the interval of equivalence, it is referred to as an equave or sometimes formal octave.
Octave stretch
Some musical systems exhibit stretched (or compressed) octaves where the octave is tuned slightly different from a pure 2:1 ratio. This occurs in piano tuning (to compensate for inharmonicity in piano strings) and in some traditional music systems, such as the Indonesian Pelog and Slendro scales.
Alternative names
Ditave is an alternative name for the interval 2/1, which was proposed to neutralize the terminology against the predominance of heptatonic scales. The name is a contraction of the numeral prefix δι- (di-, Greek for "two") and octave, in analogy to "tritave" (3/1).
Duple is a proposed term which relates itself to the ancient Greek concept of multiples. It also fixes the problem of using part of the word octave.
Diapason is another term also sometimes applied to 2/1. It is also of Greek origin, but not related to the number two; instead it is formed from διά (dia) + πασων (pason), meaning something like "through all the notes".
See also
- Prime interval
- Gallery of Just Intervals
- Toctave
- EDO
- Octave reduction
- Octave complement
- Octave (interval region)
References
- ↑ Hoeschele M. Animal Pitch Perception: Melodies and Harmonies. Comp Cogn Behav Rev. 2017
- ↑ Jacoby, Nori et al. Universal and Non-universal Features of Musical Pitch Perception Revealed by Singing. Current Biology, 2019.