music.rst
changeset 1884 75d45ff67876
child 1905 fba288d59662
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1883:2e2b67e76e55 1884:75d45ff67876
       
     1 .. -*- coding: utf-8; -*-
       
     2 .. include:: HEADER.rst
       
     3 
       
     4 ========
       
     5  Music.
       
     6 ========
       
     7 .. contents::
       
     8 
       
     9 Music scale.
       
    10 ============
       
    11 
       
    12 *Scale* is any set of musical notes ordered by fundamental frequency or pitch.
       
    13 
       
    14 Scale ordered by increasing pitch is an *ascending scale*, and a scale ordered
       
    15 by decreasing pitch is a *descending scale*.
       
    16 
       
    17 The distance between two successive notes in a scale is called a *scale step*.
       
    18 
       
    19 For Western music with 12 tones in octave used several definition of steps:
       
    20 
       
    21  * *semitone*, *half step* is 2^(1/12)
       
    22  * *whole step*, *whole tone*, *major second* is 2^(2/12)
       
    23 
       
    24 *Chromatic scale* is a musical scale with twelve pitches, each a semitone
       
    25 above or below another. On a modern piano or other equal-tempered
       
    26 instrument, all the semitones have the same size (100 cents). In other
       
    27 words, the notes of an equal-tempered chromatic scale are equally spaced.
       
    28 
       
    29  * https://en.wikipedia.org/wiki/Chromatic_scale
       
    30 
       
    31 *Diatonic scale* (or heptatonia prima) is a scale composed of seven distinct
       
    32 pitch classes: ``2–2–1–2–2–2–1``.
       
    33 
       
    34  * https://en.wikipedia.org/wiki/Diatonic_scale
       
    35 
       
    36 *Minor scale*: ``2-1-2-2-1-2-2``.
       
    37 
       
    38  * https://en.wikipedia.org/wiki/Minor_scale
       
    39 
       
    40 Pentatonic major scale: ``1, 2, 3, 5, 6``.
       
    41 Pentatonic minor scale: ``1, ♭3, 4, 5, ♭7``.
       
    42 
       
    43  * https://en.wikipedia.org/wiki/Pentatonic_scale
       
    44 
       
    45 The eight degrees of the diatonic scale are also known by traditional names:
       
    46 
       
    47  * 1st degree – Tonic (key note)
       
    48  * 2nd degree – Supertonic
       
    49  * 3rd degree – Mediant
       
    50  * 4th degree – Subdominant
       
    51  * 5th degree – Dominant
       
    52  * 6th degree – Submediant
       
    53  * 7th degree – Leading tone
       
    54  * 8th degree – Tonic (Octave)
       
    55 
       
    56 Intervals names:
       
    57 
       
    58 * *Minor second* - 1 semitones.
       
    59 * *Major second* - 2 semitones.
       
    60 * *Minor third* - 3 semitones.
       
    61 * *Major third* - 4 semitones.
       
    62 * *Perfect fourth* - 5 semitones, 4:3.
       
    63 * *Perfect fifth* - 7 semitones, 3:2.
       
    64 * *Minor sixth* - 8 semitones.
       
    65 * *Major sixth* - 9 semitones.
       
    66 * *Minor seventh* - 10 semitones.
       
    67 * *Major seventh* - 11 semitones.
       
    68 
       
    69 The notes of a scale are numbered by their steps from the root of the scale.
       
    70 
       
    71   https://en.wikipedia.org/wiki/Scale_%28music%29
       
    72     Often, especially in the context of the common practice period, most or all
       
    73     of the melody and harmony of a musical work is built using the notes of a
       
    74     single scale, which can be conveniently represented on a staff with a
       
    75     standard key signature.
       
    76   https://en.wikipedia.org/wiki/Common_practice_period
       
    77     Common-practice harmony is almost always derived from diatonic scales and
       
    78     tends to follow particular chord progressions that have withstood the test
       
    79     of time.
       
    80