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Re: Musical notes...

From ram@zedat.fu-berlin.de (Stefan Ram)
Newsgroups rec.puzzles
Subject Re: Musical notes...
Date 2026-05-27 16:25 +0000
Organization Stefan Ram
Message-ID <infos-20260527172331@ram.dialup.fu-berlin.de> (permalink)
References <10v69g9$2k4n9$2@dont-email.me>

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David Entwistle <qnivq.ragjvfgyr@ogvagrearg.pbz> wrote or quoted:
>I'm curious about the frequency (and wavelength) relationship between the 
>notes of the musical scale,

  Here's a generated list of infos, I also added something about birds.

The Fundamentals of Pitch and Ratios

Musical notes are vibrations measured in Hertz (Hz).
The relationship between two notes is called an inter‐
val, which is expressed as a mathematical frequency
ratio.

-  Octaves double frequency: Two notes an octave apart
   always have a 2:1 frequency ratio.

-  Unisons are identical: A 1:1 ratio means two notes
   share the exact same frequency.

-  Integers create consonance: Small, simple integer
   ratios sound pleasant and stable to the human ear.

-  Complexity creates dissonance: Large, complex mathe‐
   matical ratios sound tense, unstable, and harsh.

-  Pitch is logarithmic: Human perception of pitch
   scales logarithmically, not linearly, relative to
   frequency.

The Mathematics of Major Intervals (Just Intonation)
In pure tuning systems based on natural harmonics,
intervals are defined by clean, uncompromised frac‐
tions.

-  Perfect Fifth (3:2): The most stable interval after
   the octave, vibrating three times for every two of
   the base note.

-  Perfect Fourth (4:3): The inversion of a fifth,
   vibrating four times for every three of the base
   note.

-  Major Third (5:4): The bright, foundational interval
   of a major triad, vibrating five times for every
   four.

-  Minor Third (6:5): The dark, foundational interval
   of a minor triad, vibrating six times for every
   five.

-  Major Sixth (5:3): A highly consonant interval,
   vibrating five times for every three of the funda‐
   mental.

-  Major Seventh (15:8): A highly tense, complex inter‐
   val that strongly desires to resolve upward to the
   octave.

Tuning Systems and Scale Construction

Over centuries, musicians developed different systems
to organize these frequency relationships into pre‐
dictable scales.

-  Pythagorean tuning builds fifths: This ancient sys‐
   tem calculates every note by stacking pure 3:2 per‐
   fect fifths.

-  The Pythagorean comma exists: Stacking 12 perfect
   fifths does not perfectly match 7 octaves, creating
   a small mathematical overshoot.

-  Just Intonation uses fractions: This system tunes
   all notes to clean, whole‐number ratios based on a
   single fundamental note.

-  Just Intonation limits modulation: A scale tuned
   perfectly to one key sounds completely out of tune
   in another key.

-  Equal Temperament compromises physics: Modern
   12‐Tone Equal Temperament (12‐TET) mathematically
   divides an octave into 12 identical steps.

-  12‐TET uses exponents: The frequency of each consec‐
   utive semitone is multiplied by the twelfth root of
   two.

-  Only octaves stay pure: In modern 12‐TET, every sin‐
   gle interval except the octave is slightly out of
   tune with natural physics.
   
-  Modern fifths are narrow: Equal‐tempered fifths are
   roughly 2 cents flat compared to a pure 3:2 ratio.
   
-  Modern thirds are sharp: Equal‐tempered major thirds
   are nearly 14 cents sharp compared to a pure 5:4
   ratio.

Harmonics and the Overtone Series

Frequency relationships within scales are derived
directly from the physics of vibrating strings and air
columns.

-  Fundamentals dictate the pitch: The lowest, loudest
   frequency of a sound determines its perceived musi‐
   cal note.
   
-  Overtones are integer multiples: A vibrating string
   simultaneously produces frequencies at 2x, 3x, 4x,
   and 5x the fundamental.
   
-  Scales mirror the series: The major scale naturally
   emerges from the upper partials of the overtone
   series.
   
-  Timbre relies on overtones: The relative volume of
   these different frequency relationships gives
   instruments their unique sound character.

Psychoacoustics and Perception

How human brains interpret the physical interaction of
these frequencies defines musical emotion and tension.

-  Critical bands cause roughness: When two frequencies
   are too close together, the ear cannot separate
   them, creating physical friction.

-  Beating measures close pitches: Two frequencies
   slightly out of tune create a physical pulsing sen‐
   sation called beating.

-  Beat speed equals difference: The number of beats
   heard per second is exactly equal to the difference
   in Hz between the two notes.

-  Combination tones appear naturally: When two loud
   notes are played, the brain naturally perceives a
   third "difference tone" (f2-f1).

The Hidden Scales of Birdsong

To human ears, birds may seem to chirp "between the
cracks" of our musical notes, but deep acoustic analy‐
sis reveals strict underlying patterns:

-  The Harmonic Series: Species like the Hermit Thrush
   explicitly select notes that follow a harmonic
   series governed by small‐integer ratios - the exact
   same mathematical distribution that builds human
   musical scales.

-  Pentatonic and Consonant Intervals: Many birds
   default to consonant intervals (pleasant combina‐
   tions) and pentatonic structures rather than random
   frequencies.

-  Absolute Pitch vs. Spectral Shape: Humans easily
   recognize a melody if it is transposed to a differ‐
   ent octave (relative pitch).  Songbirds recognize
   melodies by "spectral shape" (timbre and texture)
   rather than moving a melody up or down a scale.

Shared Rhythms at High Speeds

Avian rhythm is incredibly precise, though it can eas‐
ily overwhelm human perception:

-  Too Fast to Track: Birds can sing up to four times
   faster than human music.  When a 2‐second wren call
   is slowed down digitally, it unfolds into a beauti‐
   fully timed, rhythmically distinct composition.

-  Isochronous Beats: Many songbirds utilize
   isochronous rhythms, where the spacing between notes
   is perfectly equidistant - just like a steady
   metronome or a drum beat.

-  Categorical Rhythms: Research published in Current
   Biology shows that songbirds like the Thrush
   Nightingale cluster their notes into rhythmic cate‐
   gories shared by human musicians, using structured
   pacing to pass songs down through generations.

The Biomechanics of the Duet

Birds possess a vocal structure completely different
from our own.  Instead of a larynx, they use a syrinx
located at the base of their trachea.  Because this
organ splits into two bronchi, a songbird can produce
two different notes simultaneously, essentially singing
their own harmony or producing complex chords that
sound like a rapid blur to us.

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Thread

Musical notes... David Entwistle <qnivq.ragjvfgyr@ogvagrearg.pbz> - 2026-05-27 08:20 +0000
  Re: Musical notes... James Dow Allen <user4353@newsgrouper.org.invalid> - 2026-05-27 12:58 +0000
    Re: Musical notes... David Entwistle <qnivq.ragjvfgyr@ogvagrearg.pbz> - 2026-05-27 18:06 +0000
      Re: Musical notes... David Entwistle <qnivq.ragjvfgyr@ogvagrearg.pbz> - 2026-05-28 10:15 +0000
  Re: Musical notes... ram@zedat.fu-berlin.de (Stefan Ram) - 2026-05-27 16:25 +0000
    Re: Musical notes... James Dow Allen <user4353@newsgrouper.org.invalid> - 2026-05-27 17:10 +0000
  Re: Musical notes... James Dow Allen <user4353@newsgrouper.org.invalid> - 2026-05-28 12:30 +0000
    Re: Musical notes... HenHanna@NewsGrouper <user4055@newsgrouper.org.invalid> - 2026-05-28 18:21 +0000
    Re: Musical notes... msb@vex.net (Mark Brader) - 2026-05-28 18:50 +0000
    Re: Musical notes... David Entwistle <qnivq.ragjvfgyr@ogvagrearg.pbz> - 2026-05-29 17:19 +0000
    Re: Musical notes... Charlie Roberts <croberts@gmail.com> - 2026-05-29 15:48 -0400
      Re: Musical notes... ram@zedat.fu-berlin.de (Stefan Ram) - 2026-05-29 20:59 +0000
        Re: Musical notes... James Dow Allen <user4353@newsgrouper.org.invalid> - 2026-05-30 12:07 +0000
          Re: Musical notes... James Dow Allen <user4353@newsgrouper.org.invalid> - 2026-05-30 12:25 +0000
            Re: Musical notes... James Dow Allen <user4353@newsgrouper.org.invalid> - 2026-05-30 12:33 +0000
            Re: Musical notes... ram@zedat.fu-berlin.de (Stefan Ram) - 2026-05-30 12:56 +0000
    Re: Musical notes... Mike Terry <news.dead.person.stones@darjeeling.plus.com> - 2026-05-29 22:38 +0100
      Re: Musical notes... David Entwistle <qnivq.ragjvfgyr@ogvagrearg.pbz> - 2026-05-30 06:38 +0000
    Re: Musical notes... Phil Carmody <pc+usenet@asdf.org> - 2026-06-05 16:41 +0300
      Re: Musical notes... James Dow Allen <user4353@newsgrouper.org.invalid> - 2026-06-05 14:54 +0000

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