MUSC&141 Creative Music Fundamentals
Pentatonic and Blues
Mark Gotham; Megan Lavengood; Brian Moseley; and Kris Shaffer
Key Takeaways
This chapter introduces a number of pitch collections that appealed to many composers in the 20th century:
- diatonic collection, as separate from major/minor scales or diatonic modes
- pentatonic collection: a five-note collection that corresponds to the black keys of the piano; can also be generated as a stack of five perfect fifths or through the pitch interval pattern 2–2–3–2–3
- The blues scale is like a minor pentatonic scale with an additional chromatic passing tone: do–me–fa–fi–sol–te
. - The blues scale can be rotated to begin on its second note, creating a major blues scale: do–re–ri–mi–sol–la
.
Pentatonic Collection
The pentatonic collection is prevalent in music across the globe. It is a collection built with the interval pattern ma2–ma2–mi3–ma2–mi3. The pentatonic collection can be described with reference to the diatonic modes in multiple different ways (Example 1).
- Using the scale degrees of a major scale, a pentatonic scale can be formed with
. - If you think of the diatonic collection as a stack of perfect fifths (F, C, G, D, A, E, B), then the pentatonic is a narrower form of the same collection: C, G, D, A, E.
- Finally, if you visualize the piano, note that the complement of C, D, E, F, G, A, B, C (the white notes) is G♭, A♭, B♭, D♭, E♭ (the black notes). The black-note collection is, once again, the pentatonic.
What the pentatonic collection removes from the diatonic is the two notes that create half steps (
and 
, if you are thinking in terms of major scale degrees). The absence of semitones arguably makes the pentatonic more readily rotatable and considered as a collection, without a strong emphasis on a particular note as tonic. Any member of the collection easily functions as a tonal center. For example, there are five unique modes of the collection given in (a) of Example 1, formed by rotating the collection so that each pitch class becomes tonic: C pentatonic (C, D, E, G, A), D pentatonic (D, E, G, A, C), E pentatonic (E, G, A, C, D), and so on. Letter (d) of Example 1 gives an especially common rotation of the pentatonic collection that is referred to as the minor pentatonic.
The pentatonic scale is especially common as a basis for melodic composition. One example can be heard during the first movement of Chen Yi’s percussion concerto, at the entrance of the strings at 2:13. Notice that the pentatonic melody is sometimes accompanied by atonal-sounding chords in the brass. Pentatonic melodies don’t need to be harmonized within the pentatonic collection, and in fact often aren’t; after all, there are only two possible triads in the pentatonic collection (C major and A minor, for example, in the collection C–D–E–G–A).
The Blues Scale
Much as the harmonies of the blues tend not to stick to one diatonic key, flouting the norms of tonal music, the melodies are similarly chromatic to match. The blues scale, notated in the upper staff of Example 4, attempts to generalize blues melodic practice into a scale on which beginning improvisers can base their melodies. The blues scale is essentially a minor pentatonic scale with an added chromatic passing tone leading up to sol 
.
This blues scale is used in both major and minor blues tunes, despite the clashes with the underlying harmony. When this scale is combined with the chords of the major blues—I, V, and IV, or C major, F major, and G major in the key of C—the characteristic clashes between mi/me 
and ti/te 
are especially notable.
These clashes often produce blue notes—notes that are not really flat or natural, but somewhere in between. Blue notes seem to split the difference between mi/me or ti/te .
The “major” blues scale
Some improvisers find it helpful to think of a major blues scale. The difference between a major and minor pentatonic scale is identical to the difference between the major and minor blues scale: the major blues scale is a rotation of the blues scale of its relative minor. Begin the blues scale on me 
, and you will get a blues scale for the relative major. These relationships are summarized in Example 5.
Compared to the minor blues scale, the major blues scale is less dissonant with major chords. When improvising, it can be helpful to think of improvising with the major blues scale over the major chords of the blues progression. But remember that using the blues scale (with flatted thirds and sevenths) over major chords is also a perfectly normal practice.
1. A scale, mode, or collection that follows the pattern of whole and half steps W–W–H–W–W–W–H, or any rotation of that pattern.
2. Belonging to the local key (as opposed to "chromatic").
A pitch collection built with the interval pattern ma2–ma2–mi3–ma2–mi3. This collection can also be generated by using scale degrees 1̂, 2̂, 3̂, 5̂, and 6̂ only of the major scale.
A type of interval that is measured in semitones. For example, the pitch interval 2 is two semitones; the pitch interval 7 is seven semitones.
A pentatonic scale with the intervals mi3–ma2–ma2–mi3–ma2. For example, starting on A, the minor pentatonic would be A–C–D–E–G. The minor pentatonic is a rotation of the major pentatonic.
A type of motion where a chord tone moves by step to another tone, then resolves by step in the same direction. For example, C–D–E above a C major chord would be an example of neighboring motion, in which D can be described as a passing tone. Entire harmonies may be said to be passing when embellishing another harmony, when the voice-leading between the two chords involves mainly passing tones (as in the passing 6/4 chord).
Notes whose exact pitch sounds somewhere between the flat and regular versions of a scale degree, particularly 3̂ and 7̂.
A scale that proceeds ma2–ma2–mi3–ma2–mi3. For example, starting on C, the C major pentatonic scale is C–D–E–G–A.
