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.
Types of pentatonic scales
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".
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:
Songs on the minor pentatonic scale include the popular children's song "Land of the Silver Birch" often sung in day care centers.
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 Scarborogh Fair (Paul Simon version), which uses the 3rd and 6th only in passing notes.
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.
Tuning
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.
Further pentatonic musical traditions
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.
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 [citation needed]. 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.
Hemitonic or anhemitonic
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).
Further reading
- 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.
