Pentatonic scale
In
music, a
pentatonic scale is a
scale with five
notes per
octave. Pentatonic scales are very common and are found all over the world, including but not limited to the tuning of the Ethiopian
krar and the Indonesian
gamelan, the melodies of African-American
spirituals,
Celtic folk music and the music of French composer
Claude Debussy.
One of the most common pentatonic scales, sometimes called a
major pentatonic scale or
primary pentatonic scale (
set form 5-35, 02479), can be constructed in many ways. A simple construction takes five consecutive pitches from the
circle of fifths; starting on C, these are C, G, D, A, and E. Transposing the pitches to fit into one
octave rearranges the pitches into the major pentatonic scale: C, D, E, G, A. In any key relative to the root, these are scale tones 1, 2, 3, 5, and 6 (root, major second, major third, perfect fifth and major sixth), and they include the root note's major triad:
Another construction, derived from
Western European classical music, begins with a
major scale and omits the fourth and the seventh
scale degrees: a C major scale is {C, D, E, F, G, A, B}, so omitting the F and B again results in the sequence {C, D, E, G, A}. The major pentatonic scale can also be seen as all the pitches that are
not present in the major scale: in C major, the remaining pitches are G flat, A flat, B flat, D flat, and E flat, the notes in the G flat major pentatonic scale. These notes are also the black keys on the
piano keyboard. This scale is used for many popular pentatonic songs such as "
Amazing Grace" and "
Auld Lang Syne".
|
Gb major pentatonic scale |
Another variation of the pentatonic scale is to take the major scale and remove the third and seventh, to obtain the notes {C,D,F,G,A}.
There are two different pentatonic scales in common usage that are referred to as
minor. One is the relative minor pentatonic derived from the major pentatonic, using scale tones I, iii, IV, V, vii (root, minor third, perfect fourth, perfect fifth, minor seventh) relative to the
tonic. Thus C minor pentatonic would be C, Eb, F, G, Bb; A minor pentatonic, the relative minor of C, would be the same tones as C major pentatonic, starting on A, giving A, C, D, E, G. This minor pentatonic contains all three tones of the root note's minor triad:
Just as there are 7 diatonic
modes, there are 5 pentatonic modes: Major (C D E G A), thirdless with major sixth (C D F G A), thirdless with minor seventh (C D F G Bb), minor (C Eb F G Bb) and fifthless (C Eb F Ab Bb). They can also be named by their corresponding diatonic cousins: Ionian pentatonic, Mixolydian pentatonic, Dorian pentatonic, Aeolian pentatonic and Phrygian pentatonic. The logic here is that the Dorian scale starts on the 2nd degree of the Ionian scale, just like in the diatonic system. An example of a song based on the Dorian pentatonic scale is
Scarborough Fair (Paul Simon version), which uses the 3rd and 6th notes only in passing.
Songs on the minor pentatonic scale include the popular children's song "
Land of the Silver Birch" often sung in day care centers. Because of their simplicity, pentatonic scales are often used to introduce children to music. Other popular children's songs are almost pentatonic. For example, the almost-pentatonic nature of the
Gershwin lullaby "
Summertime", is evident when it is played in the key of E-flat. In that key, the melody can be played almost entirely on the black keys of a piano, except just once per verse, where a white key is needed.
Another common minor pentatonic is constructed from the scale tones I, II, iii, V, VI.
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 major and minor pentatonic scales possess
Myhill's property.
The
blues scale is the minor pentatonic with an additional augmented fourth, which is referred to as the "blue note" A, C, D, D#, E, G, A:
|
Pentatonic blues scale on A |
The minor pentatonic scale is also, however, sometimes referred to as the blues scale.
Deriving the pitches in a pentatonic scale from stacked fifths leads to a Pythagorean scale of {1/1, 9/8, 81/64, 3/2, 27/16}. Deriving the pitches from the major scale leads to a just scale of either {1/1, 9/8, 5/4, 3/2, 5/3} (a
5-limit pentatonic) or {1/1, 9/8, 21/16, 3/2, 7/4} with
blue notes of the flatted fourth and flatted seventh. The blues scale can be tuned {1/1, 7/6, 4/3, 7/5, 3/2, 7/4}. There is also the pentatonic scale used by the
Wagogo people of Tanzania who tune their instruments thus: {1/1, 9/8, 5/4, 3/2, 7/4}. This anhemitonic scale can be thought of as a section of the harmonic series, from the 5th or 6th overtone up to the 10th, transposed to other octaves.
The pentatonic scale is very common in
Scottish music. Some scholars believe that English
folk music was likewise at one time a pentatonic tradition; for the reasoning behind this claim, see
folk music.
The major pentatonic scale is the basic scale of the
music of China; the minor pentatonic is used in
Appalachian folk music. The fundamental tones (without
meri or
kari techniques) rendered by the 5 holes of the
Japanese shakuhachi flute play a minor pentatonic scale. The
Yo scale used in Japanese
shomyo Buddhist chants and
gagaku imperial court music is a pentatonic scale, shown below.
[Japanese Music, Cross-Cultural Communication: World Music, University of Wisconson - Green Bay]Both the major and the minor pentatonic scales are commonly used in
jazz (notably by jazz pianists
Chick Corea and
Herbie Hancock),
blues, and
rock. Pentatonic scales are useful in modern jazz and pop/rock contexts because they work exceedingly well over several chords
diatonic to the same key, often better than the parent scale. For instance, over a C major triad (C, E, G) in the key of C major, the note F can be perceived as dissonant as it is a half step above the major third (E) of the chord. This becomes a common avoid note for that scale. (F can be allowed in some
modal musical contexts, where it is a characteristic note of the C Ionian mode). Using the major pentatonic scale is an easy way out of this problem. The scale tones 1, 2, 3, 5, 6 (from major pentatonic) are either major triad tones (1, 3, 5) or common consonant extensions (2, 6) of major triads. For the corresponding relative minor pentatonic, scale tones 1, b3, 4, 5, b7 work the same way, either as minor triad tones (1, b3, 5) or as common extensions (4, b7), as they all avoid being a half step from a chord tone.
The pentatonic scale plays a significant role in
music Education, particularly in
Orff-based methodologies at the
primary/elementary level. The
Orff system places a heavy emphasis on developping creativity through
improvisation in children, largely through use of the pentatonic scale.
Orff instruments, such as
xylophones and other
metallophones, use wooden bars which can be removed by the teacher leaving only those corresponding to the pentatonic scale, which
Orff himself believed to be children's native tonality . Children begin improvising using only these bars, and over time, more bars are added at the teacher's discretion until the complete
diatonic scale is being used.
Orff believed that the use of the pentatonic scale at such a young age was appropriate to the development of each child, since the nature of the scale meant that it was impossible for the child to make any real
harmonic mistakes
The pentatonic scales used in
Indonesian
gamelan music are called
slendro and
pelog.
Composers of Western
classical music have occasionally used the pentatonic scale for special effects.
Maurice Ravel used it as a
pastiche of Chinese music in "Laideronette, Emperatrice des Pagodes", a movement from his "
Ma Mère l'Oye" (Mother Goose) suite for
orchestra.
Frédéric Chopin wrote the right hand piano part of his
Etude Op. 10 no. 5 in the major G flat pentatonic scale--hence, using only the black keys.
Blackfoot music is most often pentatonic or
hexatonic.
Pentatonic scales may be characterized as
hemitonic or
anhemitonic. Hemitonic scales contain one or more
semitones and anhemitonic scales do not contain semitones. For example, a hemitonic pentatonic scale common in some areas of North and West Africa contains a flatted 2nd, 3rd, and 6th (hence, if the scale begins in C, it will contain a D flat, E flat, and A flat, plus a G natural).
*Tran van Khe (1977). "Le pentatonique est-il universel? Quelques reflexions sur le pentatonisme",
The World of Music 19, nos. 1-2:85-91. English translation p.76-84
*Kurt Reinhard, On the problem of pre-pentatonic scales: particularly the third-second nucleus, Journal of the International Folk Music Council 10, 1958.
