Consonance and dissonance: Difference between revisions

Fredg999 category edits (talk | contribs)
m Removing from Category:Sonance using Cat-a-lot
m Vertical fractions only have a place in display-style math
 
(25 intermediate revisions by 6 users not shown)
Line 3: Line 3:


== Sonance ==
== Sonance ==
[[Joe Monzo]] considers consonance and dissonance to be opposite poles of a continuum of sensation, which he calls '''sonance'''. However he was not the first who used the term ''sonance'': also [https://de.wikipedia.org/wiki/Wilhelm_Keller_%28Komponist%29 Wilhelm Keller] distinguishes between ''sonanzmodal'' and ''distanzmodal'' aspects when analysing sounds, see his ''Handbuch der Tonsatzlehre'' from 1957.
[[Joseph Monzo]] considers consonance and dissonance to be opposite poles of a continuum of sensation, which he calls '''sonance'''. However he was not the first who used the term ''sonance'': also [https://de.wikipedia.org/wiki/Wilhelm_Keller_%28Komponist%29 Wilhelm Keller] distinguishes between ''sonanzmodal'' and ''distanzmodal'' aspects when analysing sounds, see his ''Handbuch der Tonsatzlehre'' from 1957.


The term ''sonance'' goes back to [[Wikipedia:Giovanni Battista Benedetti|Giovanni Battista Benedetti]]:<ref>[http://xtf.lib.virginia.edu/xtf/view?docId=DicHist/uvaBook/tei/DicHist3.xml;chunk.id=dv3-32 http://xtf.lib.virginia.edu/xtf/view?docId=DicHist/uvaBook/tei/DicHist3.xml;chunk.id=dv3-32]</ref>
The term ''sonance'' goes back to [[Wikipedia:Giovanni Battista Benedetti|Giovanni Battista Benedetti]]:<ref>[http://xtf.lib.virginia.edu/xtf/view?docId=DicHist/uvaBook/tei/DicHist3.xml;chunk.id=dv3-32 http://xtf.lib.virginia.edu/xtf/view?docId=DicHist/uvaBook/tei/DicHist3.xml;chunk.id=dv3-32]</ref>
Line 10: Line 10:


== Musical vs. sensory dissonance ==
== Musical vs. sensory dissonance ==
Musical dissonance is a complex phenomenon depending on not only the fundamental frequency ratio but also the register, timbres, volume, spatialization, and the listener's conditioning and cultural background. '''Sensory dissonance''', '''discordance''', '''discord''', or '''roughness''', however, is a psychoacoustic effect that is much more consistent among most human listeners except for those with conditions like congenital amusia (tone deafness). In its most basic form, sensory dissonance occurs when two sine wave tones in the audible frequency range are played simultaneously, within about a critical band of each other but far apart enough that beating is not audible. The opposite is '''sensory consonance''', '''concordance''', '''concord''' or '''smoothness'''. '''''Cordance''''' has been proposed by [[User:Inthar|Inthar]] as a term for the degree of psychoacoustic concordance and discordance, by analogy with the term ''sonance'' (see above), to lessen the common confusion between psychoacoustic concordance/discordance and musical consonance/dissonance.


Musical dissonance is a complex phenomenon depending on not only the fundamental frequency ratio but also the register, timbres, volume, spatialization, and the listener's conditioning and cultural background. '''Sensory dissonance''' or '''roughness''', however, is a psychoacoustic effect that is much more consistent among most human listeners except for those with conditions like congenital amusia (tone deafness). In its most basic form, sensory dissonance occurs when two sine wave tones in the audible frequency range are played simultaneously, within about a critical band of each other but far apart enough that beating is not audible.
A study by Kameoka & Kuriyagawa in 1969 had listeners grade the roughness of two sine waves played simultaneously at equal intensity. They computed that if the lower sine wave has frequency ''f''<sub>1</sub> Hz, then the upper frequency that maximizes roughness is about {{nowrap|''f''<sub>2</sub> {{=}} ''f''<sub>1</sub> + 2.27{{subsup|''f''|1|0.477}}}} (we will call this the ''maximal roughness formula''). This assumes that each sine wave has intensity 57 dB SPL; the formula changes slightly depending on volume. The interval ''f''<sub>2</sub>/''f''<sub>1</sub> is about 1.56 semitones at 440 Hz, and narrows as frequency increases.


A study by Kameoka & Kuriyagawa in 1969 had listeners grade the roughness of two sine waves played simultaneously at equal intensity. They computed that if the lower sine wave has frequency ''f''<sub>1</sub> Hz, then the upper frequency that maximizes roughness is about <math>f_2 = f_1 + 2.27 f_1^{0.477}\ \text{Hz}</math> (we will call this the ''maximal roughness formula''). This assumes that each sine wave has intensity 57 dB SPL; the formula changes slightly depending on volume. The interval <math>f_2/f_1</math> is about 1.56 semitones at 440 Hz, and narrows as frequency increases.
The same authors propose a measurement of sensory dissonance between two arbitrary sine waves, broadly modeled as follows: two identical frequencies have a dissonance of 0, the maximal roughness formula gives a dissonance of 1, and two frequencies at an octave or greater have dissonance 0. From zero difference to maximal roughness linear interpolation is used, and from maximal roughness to an octave a gradual decay. Note, however, that this is the result of one study; subsequent replication attempts have produced somewhat different formulas, and this particular study has been critically re-evaluated such as by [https://kb.osu.edu/bitstream/handle/1811/24077/EMR000007a-mashinter.pdf?sequence=1 Mashinter in 2006].
 
The same authors propose a measurement of dissonance between two arbitrary sine waves, broadly modeled as follows: two identical frequencies have a dissonance of 0, the maximal roughness formula gives a dissonance of 1, and two frequencies at an octave or greater have dissonance 0. From zero difference to maximal roughness linear interpolation is used, and from maximal roughness to an octave a gradual decay. Note, however, that this is the result of one study; subsequent replication attempts have produced somewhat different formulas, and this particular study has been critically re-evaluated such as by [https://kb.osu.edu/bitstream/handle/1811/24077/EMR000007a-mashinter.pdf?sequence=1 Mashinter in 2006].


To address some possible misconceptions, sensory dissonance is not musical dissonance, and it has nothing to do with approximation to e.g. JI intervals. It's specifically about the basilar membrane's ability to separate nearby partials. Sensory dissonance only happens when the constituent tones are played simultaneously, not necessarily in succession. Also, it's important that the partials have comparable volumes; if one is much quieter than the other, then it may be masked. Sensory dissonance models for three or more partials quickly get very complicated, and designing good experiments is challenging.
To address some possible misconceptions, sensory dissonance is not musical dissonance, and it has nothing to do with approximation to e.g. JI intervals. It's specifically about the basilar membrane's ability to separate nearby partials. Sensory dissonance only happens when the constituent tones are played simultaneously, not necessarily in succession. Also, it's important that the partials have comparable volumes; if one is much quieter than the other, then it may be masked. Sensory dissonance models for three or more partials quickly get very complicated, and designing good experiments is challenging.
Line 25: Line 24:


== See also ==
== See also ==
* [[Tenney height]]
* [[Tenney height]], a [[complexity]] measure on JI intervals
* [[A singular measure of dissonance]]
* [[Harmonic entropy]], referring to either a concordance metric on intervals and chords or the psychoacoustic model used to compute it
* [[Harmonic Entropy]]
* [[Saddle chord]], a type of chord that exploits harmonic entropy
* ''[[A singular measure of dissonance]]'' (2018)


== External links ==
== External links ==