In
music theory, a diatonic scale
is a
scale whose notes are built on
the natural
staff positions of lines and
spaces, with no
accidentals, with or without a
key signature. These scales are
based on concepts developed by
Guido d'Arezzo, and are therefore
sometimes referred to as Guido scales. Diatonic music is
written primarily using the notes from a diatonic scale;
similarly, diatonic
chords and diatonic
intervals use notes from such a
scale. The antonym is
chromatic.
Diatonic scales are a fundamental building block
of the European
musical tradition. It is
sometimes used to refer to all the
modes, but is generally used only
in reference to the major and minor scales. It contains seven
notes to the
octave, corresponding to the
white keys on a
piano, obtained from a
chain of six successive
fifths in some version of
meantone temperament, and
resulting in two
tetrachords separated by
intervals of a
whole tone. If our version of
meantone is the twelve tone
equal temperament the pattern of
intervals in
semitones will be 2-2-1-2-2-2-1.
The
major scale begins on the first
note and proceeds by steps to the first octave. In
solfege, the syllables for each
scale degree are "Do-Re-Mi-Fa-Sol-La-Ti-Do".
The
natural minor scale can be
thought of in two ways, the first is as the relative minor
of the major scale, beginning on the sixth degree of the scale and
proceeding step by step through the same tetrachords to the first
octave of the sixth degree. In solfege "La-Ti-Do-Re-Mi-Fa-Sol."
Alternately, the natural minor can be seen as a composite of two
different tetrachords of the pattern 2-1-2-2-1-2-2. In solfege
"Do-Re-Mé-Fa-Sol-Lé-Té-Do."
Western
harmony from the
Renaissance up until the
late nineteenth century is based
upon the diatonic scale and the unique
hierarchical relationships
created by this system of organizing seven notes. It should be
kept in mind that most longer pieces of common practice music
change key, but this leads to a
hierarchical relationship of diatonic scales in one key with those
in another.
These unique relationships are as follows: Only
certain divisions of the octave, 12 and 20 included, allow
uniqueness, coherence, and transpositional simplicity, and that
only the diatonic and pentatonic subsets of the 12 tone chromatic
set follow these constraints (Balzano, 1980, 1982). The diatonic
collection contains each interval class a unique number of times
(Browne 1981 cited in Stein 2005, p.49, 49n12).
Diatonic set theory describes the
following properties:
maximal evenness,
Myhill's property,
well formedness, the
deep scale property,
cardinality equals variety, and
structure implies multiplicity.
See also