4 ms·

For this exact reason, in music theory, the perfect fifth is seen as a note that amplifies/emboldens the root note of a chord and does not add a particular harm

by stfwn 8y ago

For this exact reason, in music theory, the perfect fifth is seen as a note that amplifies/emboldens the root note of a chord and does not add a particular harmonic color. In jazz it's often left out to open up chords more (i.e. not muddy the frequency distribution with too many adjacent notes unless you explicitly want the powerful sound). In pop the nondescript nature is used to create a strong sense of grounding in the scale; the root note of the scale and its fifth fit over every possible diatonic root note (play c-g in your right hand with root notes c,f,a,g in the left one after the other, it will sound familiar). In rock they literally call the perfect fifth a 'power chord' and they play melodies with it. It fattens up the melody note without adding any harmonic identity that would create tension with the rest of the harmonic content of the song.

baddox 8y ago
For sure. It still doesn't explain why the octave is the specific point where the cycle of pitch perception repeats. The perfect fifth is very consonant, for sure, but there is no "perfect fifth equivalence" in any musical traditional as far as I know.
- kazinator 8y ago
  Note that there is no harmonic that is a perfect fifth above the fundamental; the first harmonic is the octave. So if cycles of perception have to be based on harmonics (multiples of frequencies), the next plausible one after octaves (2f) would be based on the perfect 12 (3f), rather than the 5th (3f/2). The 4f based cycle is really just octaves again, except we're skipping every other octave. It gets too distant after that. Maybe the 3f progression does contain a cycle of pitch perception; I will try giving that a listen.
  - kazinator 8y ago
    I tried this! Eerily, I'm able to convince my ear/brain that this 12th interval is an octave-like relationship; that the two notes have a sameness (that I don't perceive in the case of the perfect fifth that we normally consider enharmonic with the 12th, giving it the same letter name). Come to think of it, a lot of western harmony is based on a two-octave "gamut". Like for instance alterations to chords such as dominants take place close to this "3f octave" (dodecade?) 12th interval, like the like 11th, 13th. The usual explanation is that if these alterations are in the higher octave, it prevents certain dissonances. But from the "3f octave" view, we can just regard them as different notes; that the 13th is not simply the 6th, only one octave higher, but rather an "augmented dodecave" interval.

by stfwn 8y ago

baddox 8y ago

For sure. It still doesn't explain why the octave is the specific point where the cycle of pitch perception repeats. The perfect fifth is very consonant, for sure, but there is no "perfect fifth equivalence" in any musical traditional as far as I know.

kazinator 8y ago
Note that there is no harmonic that is a perfect fifth above the fundamental; the first harmonic is the octave. So if cycles of perception have to be based on harmonics (multiples of frequencies), the next plausible one after octaves (2f) would be based on the perfect 12 (3f), rather than the 5th (3f/2). The 4f based cycle is really just octaves again, except we're skipping every other octave. It gets too distant after that. Maybe the 3f progression does contain a cycle of pitch perception; I will try giving that a listen.
- kazinator 8y ago
  I tried this! Eerily, I'm able to convince my ear/brain that this 12th interval is an octave-like relationship; that the two notes have a sameness (that I don't perceive in the case of the perfect fifth that we normally consider enharmonic with the 12th, giving it the same letter name). Come to think of it, a lot of western harmony is based on a two-octave "gamut". Like for instance alterations to chords such as dominants take place close to this "3f octave" (dodecade?) 12th interval, like the like 11th, 13th. The usual explanation is that if these alterations are in the higher octave, it prevents certain dissonances. But from the "3f octave" view, we can just regard them as different notes; that the 13th is not simply the 6th, only one octave higher, but rather an "augmented dodecave" interval.