Musical scale
In
music, a
scale is a set of
musical
notes that provides material for part or all of a musical work. Scales are typically ordered in
pitch, with their ordering providing a measure of musical distance. Scales differ from
modes in that scales do not have a primary or "tonic" pitch. Thus a single scale can have many different modes, depending on which of its notes is chosen as primary.
The distance between two successive notes in a scale is called a "scale step." Composers often transform musical patterns by moving every note in the pattern by a constant number of scale steps: thus, in the C major scale, the pattern C-D-E (
"doe, a deer") might be shifted up a single scale step to become D-E-F ("ray, a drop"). Since the steps of a scale can have various sizes, this process introduces subtle melodic and harmonic variation into the music. This variation is what gives scalar music much of its complexity.
Scales may be described according to the
intervals they contain:
* for example:
diatonic,
chromatic,
whole toneor by the number of different
pitch classes they contain:
* most common:
pentatonic,
hexatonic,
heptatonic or five, six, and seven tone scales, respectively.
*used in
prehistoric music:
ditonic or two,
tritonic or three,
tetratonic or four
*most commonly in
jazz and
modern classical music:
octatonic or eight.
Scales are often abstracted from
performance or
composition, though they are often used
precompositionally to guide or limit a composition. One or more scales may be used in a composition, such as in
Claude Debussy's
L'Isle Joyeuse. Below, the first scale is a whole tone scale, while the second and third scales are diatonic scales. All three are used in the opening pages of Debussy's piece.
|
The lydian mode, middle, functions as an intermediary between the whole tone scale, top, and the major scale, bottom. |
Musicians use the term "scale" in several incompatible senses.
Scale vs. Mode. Sometimes the term refers to an ordered collection in which no element has been chosen as primary. Thus musicians will talk about the "diatonic scale," the "octatonic scale," or the "whole tone scale." However, the term is sometimes used to mean "mode," indicating that an element of the scale has been chosen as most important. Thus the "C major scale" and the "A natural minor scale" contain the same notes; the difference between them consists only in which note is assigned primacy. Similarly, jazz musicians use the term
altered scale to refer to the seventh mode of the ascending melodic
minor scale. For consistency, this article will use the term "scale" to refer to an ordered collection with no "primary" or "tonic" note.
Scale vs. Scale Type. Sometimes the term "scale" refers to a specific ordered collection of pitches. For instance, the "C diatonic scale" contains the pitch classes C-D-E-F-G-A-B and no others, while the "G diatonic scale" contains the pitch classes G-A-B-C-D-E-F# and no others. However, the term "scale" is also used to refer to
types of scale related by
transposition. In this sense, musicians will talk about
the diatonic scale, considering the C diatonic scale and G diatonic scale to be instances of a single, larger category. Consistency suggests distinguishing a "scale" (such as C or G diatonic) from "scale type" (
the diatonic scale-type"). To avoid neologisms, however, we will follow traditional musical practice, using the term "scale" in both senses. Context should allow readers to distinguish between particular scales and the larger types to which they belong.
In addition, the term "scale" is used in
psychoacoustics to refer to various ways of measuring distances between pitches. See
bark scale and
mel scale.
Scales in
traditional Western music generally consist of seven notes and repeat at the octave. Notes in the commonly used scales (see just below) are separated by
whole and half step intervals of
tones and
semitones (the harmonic minor scale including a three-semitone interval; the pentatonic including two of these). Notes with one note between them are separated by three or four semitones.
Traditional Western classical music uses just three types of scale:
*The
diatonic scale (seven notes)
*The melodic and harmonic
minor scales (seven notes)
In the nineteenth and twentieth century, additional types of scale become common:
*The
chromatic scale (twelve notes)
*The
whole tone scale (six notes)
*The
pentatonic scale (five notes)
*The octatonic or
diminished scales
A large — indeed, virtually endless — variety of other scales exist:
*The
Phrygian dominant scales (this is in fact a mode of the harmonic minor scale)
*The
Arabic scales
In many musical circumstances, a specific note of the scale will be chosen as the "tonic"--the central and most stable note of the scale. Relative to a choice of tonic, the notes of a scale are often labeled with numbers recording how many scale steps above the tonic they are. For example, the notes of the C diatonic scale (C, D, E, F, G, A, B) can be labeled {1, 2, 3, 4, 5, 6, 7}, reflecting the choice of C as tonic. The term "scale degree" refers to these numerical labels. In the C diatonic scale, with C chosen as tonic, C is the first scale degree, D is the second scale degree, and so on.
Note that such labeling requires the choice of a "first" note; hence scale-degree labels are not intrinsic to the scale itself, but rather to its modes. For example, if we choose A as tonic, then we can label the notes of the C diatonic scale using A = 1, B = 2, C = 3, D = 4, and so on. However, the
difference between two scale degrees is independent of the choice of scale degree 1. Thus whether two notes are adjacent in a scale, or separated by one note, does not depend on the mode under discussion.
The scale degrees of the traditional major scale can also be named using the terms
tonic, supertonic, mediant, subdominant, dominant, submediant,
leading-tone (or leading-note). Also commonly used is the "movable doh"
solfege naming convention in which each scale degree is given a syllable. In the major scale, the solfege syllables are: Do, Re, Mi, Fa, So (or Sol), La, Ti (or Si), Do (or Ut).
In traditional Western music, scale notes are most often separated by equally-tempered tones or semitones, creating at most, twelve pitches. Many other musical traditions employ scales that include other intervals or a different number of pitches. In the middle eastern
Hejaz scale, there are some intervals of three semitones.
Gamelan music uses a small variety of scales including
Pélog and
Sléndro, none including equally tempered intervals.
Ragas in
Indian classical music often employ intervals smaller than a semitone (Callow & Sheperd, 1972; Jhairazbhoy & Stone, 1963).
Arab music maqams may use
quarter tone intervals (Zonis, 1973). In both ragas and maqams, the distance between a note and an inflection (e.g.,
śruti) of that same note may be less than a semitone.
The term
microtonal music usually refers to music with roots in traditional Western music that employs non-standard scales or scale intervals. The
composer Harry Partch made custom
musical instruments to play compositions that employed a 43-note scale system, and the
American jazz
vibraphonist Emil Richards experimented with such scales in his 'Microtonal Blues Band' in the
1970s.
John Cage, the American experimental composer, also created works for
prepared piano which use varied, sometimes random, scales. Microtonal scales are also used in traditional Indian
Raga music, which has a variety of modes which are used not only as
modes or scales but also as defining elements of the
song, or
raga.
Through the introduction of
blue notes,
jazz and
blues employ scale intervals smaller than a semitone.
See also:
jazz scales. The blue note is an
interval that is technically neither
major or
minor but 'in-between', giving it a characteristic flavour. For instance, in the
key of E, the blue note would be either, a note between G and G# or a note moving between both. In blues a
pentatonic scale is often used. In jazz many different
modes and scales are used, often within the same piece of music. Chromatic scales are common, especially in modern jazz.
As discussed above, musicians often utilize scales by shifting (transposing) a musical pattern by some constant number of scale steps. This process is known as
scalar transposition.
The harmonies of traditional tonal music are constructed in this way. Western tonal
chords are stacks of
thirds built above a particular
scale degree, which is called the
root of the harmony. Thus in a C diatonic scale: CDEFGAB, a three-note chord built on C will consist of the notes C-E-G. The same pattern, built on the note G, produces the harmony G-B-D.
*Burns, Edward M. (1999). "Intervals, Scales, and Tuning",
The Psychology of Music second edition. Deutsch, Diana, ed. San Diego: Academic Press. ISBN 0122135644.
*Zonis, E. (1973).
Classical Persian music: An Introduction. Cambridge, MA: Harvard University Press.
*
History of music*
Prehistoric music*
Divje Babe*
Musical Acoustics*
Jiahu Site of oldest still-playable flute -- Neolithic
* http://musicianswiki.com/index.php/scales Lots of scales (including exotic ones) with midi examples.
*
Piano Scales*
Jazz Scales* http://www.skytopia.com/project/scale.html
* http://home.austin.rr.com/jmjensen/musicTheory.html
* http://www.greenwych.ca/natbasis.htm (Evolution of Scales)
* http://www.greenwych.ca/cycl-5-2.htm (7-Note Solution -- why history & archaeologists turns up so many 5 and 7 note scales)
* http://www.greenwych.ca/fl-compl.htm (Oldest known "Neanderthal flute" plays do-re-mi-fa scale notes.)
*
Guitar scales at GOSK.com
