A jazz scale is any musical scale used in jazz. Many "jazz scales" are common scales drawn from Western European classical music, including the diatonic, whole-tone, octatonic (or diminished), and the modes of the ascending melodic minor. All of these scales were commonly used by late nineteenth and early twentieth-century composers such as Rimsky-Korsakov, Debussy, Ravel and Stravinsky, often in ways that directly anticipate jazz practice. Some jazz scales, such as the bebop scales, add additional chromatic passing tones to the familiar diatonic scales.
One important feature of jazz is what theorists call "the principles of chord-scale compatibility": the idea that a sequence of chords will generate a sequence of compatible scales. In classical major-mode harmony, chords typically belong to the same scale. (For example, a ii-V-I progression in C major will typically use only the notes of the C diatonic collection.) In jazz, a four-chord progression may use four different scales, often as the result of chordal alterations. For instance, in C major, a jazz musician may alter the V chord G-B-D-F with a flattened fifth, producing G-B-D♭-F. An improviser might then choose a scale containing these four notes, such as G whole tone (G-A-B-C♯-D♯-F), G octatonic [or symmetric diminished] (G-A♭-B♭-B-C♯-D-E-F), or a mode of either D or A♭ melodic minor ascending (G-A-B-C♯-D-E-F or G-A♭-B♭-C♭-D♭-E♭-F respectively). In each case the scale contains the chord tones G-B-D♭-F and is said to be compatible with it. This notion of "chord scale compatibility" marks a fundamental difference between jazz harmony and traditional classical practice.
An avoid note is a note in a jazz scale that is considered, in jazz theory and practice, too dissonant to be played against the underlying chord, and so is either avoided or chromatically altered. For example, in major-key harmony the fourth, and thus 11th, is an avoid note and thus either treated as a passing tone or augmented (raised a semitone). Avoid notes are often a minor second (or a minor ninth) above a chord tone or a perfect fourth above the root of the chord.
[One] can get a good sense of the difference between classical and non-classical harmony from looking at how they deal with dissonances. Classical treats all notes that don't belong to the chord (i.e., the triad) as potential dissonances to be resolved. ... Non-classical harmony just tells you which note in the scale to avoid ["what is sometimes called an avoid-note"] (because it's really dissonant), meaning that all the others are okay.
The number of scales available to improvising musicians continues to expand. As modern techniques and musical constructions appear, jazz players find the ones they can put into compositions or use as material for melodic exploration. Prominent examples are the seven modes of the diatonic major scale and added-note scales.
|I||Ionian mode||C D E F G A B C||(associated with C Major 7 (9, 13) chord)|
|II||Dorian mode||C D E♭ F G A B♭ C||(associated with C-6 or C-7 (9, 11, 13) chord)|
|III||Phrygian mode||C D♭ E♭ F G A♭ B♭ C||(associated with C-7 (11) chord)|
|IV||Lydian mode||C D E F♯ G A B C||(associated with C Maj7 (9, ♯11, 13) chord)|
|V||Mixolydian mode||C D E F G A B♭ C||(associated with C7 (9, 13) chord)|
|VI||Aeolian mode||C D E♭ F G A♭ B♭ C||(associated with C-7 (9, 11)|
|VIIø||Locrian mode||C D♭ E♭ F G♭ A♭ B♭ C||(associated with C-7♭5 (11, b13) chord)|
Compare each of the modes to the major scale for clues as to the subtle differences between them. Ionian is based on the 1st degree of the major scale, Dorian on the 2nd, Phrygian on the 3rd, etc.
|C Ionian||C D E F G A B C||(associated with C Major 7 (9, 13) chord)|
|D Dorian||D E F G A B C D||(associated with D-6 or D-7 (9, 11, 13) chord)|
|E Phrygian||E F G A B C D E||(associated with E-7 (11) chord)|
|F Lydian||F G A B C D E F||(associated with F Maj7 (9, ♯11, 13) chord)|
|G Mixolydian||G A B C D E F G||(associated with G7 (9, 13) chord)|
|A Aeolian||A B C D E F G A||(associated with A-7 (9, 11) chord)|
|B Locrian||B C D E F G A B||(associated with B-7♭5 (11, b13) chord)|
Bebop scales add a single chromatic passing tone to the 7 note major scale (Ionian and Mixolydian modes). The added passing tone creates an 8 tone scale that fits rhythmically evenly within a 4/4 measure of eight 8th notes, thus making it useful in practicing. When an 8th note bebop scale run starts on the beat from a chord tone (Root, 3rd, 5th or ♭7th) the other chord notes will also fall on the beats. As a result, all of the "non-chord tones" will fall on the upbeats (the "ands" when counting "one and two and three and four and") and become passing tones.
There are two commonly used types of bebop scales:
Dominant bebop scale, which adds the raised 7th to Mixolydian: Ascending: 1 2 3 4 5 6 ♭7 7 (8) Descending: 8 ♭7 6 ♭6 5 4 3 2 (1)
Major bebop scale, which adds ♯5 to Ionian: 1 2 3 4 5 ♯5 6 7 (8)
NOTE: A dominant bebop scale works well over an entire ii V.
A great deal of modern jazz harmony arises from the modes of the ascending form of the melodic minor scale, also known as the jazz melodic minor scale. (see jazz minor scale) This scale is essentially a diatonic major scale with a flatted third, for example C D E♭ F G A B C. As with any other scale, the modes are derived from playing the scale from different root notes, causing a series of jazz scales to emerge.
Modes of C ascending melodic minor:
|I||Ascending Melodic Minor||T, 2,♭3, 4, 5, 6, 7||(associated with C-maj7 (9, 11, 13) or C-6 chords, functions as a i minor)|
|II||Phrygian ♮6, Dorian ♭2, Assyrian, or Phrygidorian||T,♭2,♭3, 4, 5, 6,♭7||(associated with D7sus (b9,#9, 13) chord, with b2 as a non-chord tone producing a minor ninth)|
|III||Lydian augmented or Lydian ♯5||T, 2, 3,♯4,♯5, 6, 7||(associated with Eb maj7+5 (9, 11) chord, functions as a III+)|
|IV||Lydian dominant, Lydian ♭7, Acoustic scale, Mixolydian ♯4, Overtone, or Lydomyxian||T, 2, 3,♯4, 5, 6,♭7||(associated with F7 (9, ♯11, 13) chord, functions as a dominant, secondary, or substitute dominant)|
|V||Mixolydian ♭6, melodic major, fifth mode of melodic minor, Hindu, or Myxaeolian||T, 2, 3, 4, 5,♭6,♭7||(associated with G7 (9, ♭13) chord, functions as a dominant with b13 as a non-chord tone or the fifth avoided in the chord voicing as they produce a minor ninth)|
|VI||Locrian ♮2, half-diminished, or Aeolocrian||T, 2,♭3, 4, ♭5,♭6,♭7||(associated with A-7♭5 (9, 11, b13), which functions as a ii chord in the fifth mode of melodic minor)|
|VII||Super Locrian, altered dominant scale, or altered scale||T,♭2,♭3, ♭4,♭5,♭6,♭7||(associated with B7 (♯ or ♭9, ♯11, ♭13) chord, functions as a dominant with the fifth of the chord replaced by #11 or b13, may also be used to harmonize a VII-7b5 chord in melodic minor)|
It should be noted that the names of these scales are variations of the names used for some of the modes of the diatonic major scale, for example the Phrygian Natural 6, the second mode of the melodic minor, is named so because it is the same as the Phrygian mode of the major scale except with a raised (i.e.,♮6) sixth.
There are two types of symmetric diminished scales. These scales are sometimes called octatonic scales because they contain eight tones. They are based on a series of alternating half steps and whole steps. One type starts with a half-step (H-W-H-W-H-W-H-W), and one starts with a whole step (W-H-W-H-W-H-W-H).
Because of the repetition of the interval pattern after only two notes, each note in the scale can be a root in another symmetric diminished scale. For example, the C symmetric diminished scale of the half-step-first type, is composed with the same notes as the half-step-first type E♭ scale, and the whole-step-first type D♭ scale:
E♭ symmetric (half, whole) diminished: E♭ E F♯ G A B♭ C D♭ E♭
D♭ symmetric (whole, half) diminished: D♭ E♭ E F♯ G A B♭ C D♭
All three are composed with the same group of notes: C D♭ E♭ E F♯ G A B♭ C
In fact, all symmetric diminished scales are composed of three groups of notes as follows:
C D♭ E♭ E F♯ G A B♭ C
C D E♭ F F♯ G♯ A B C
D♭ D E F G A♭ B♭ C♭ D♭
The whole tone scale, consisting exclusively of whole steps, is often used on V7 +6 chords (G7 + for example).
Two pentatonic scales common to jazz are the major pentatonic scale and the minor pentatonic scale. They are both modes to each other, respectively.
The major pentatonic scale begins with a major scale and omits the fourth and the seventh scale degrees. The C major scale is ( C, D, E, F, G, A, B ), so the C major pentatonic scale is ( C, D, E, G, A ) :
The minor pentatonic scale uses the same notes as the major pentatonic scale, but begins on the sixth scale degree of the corresponding major scale. Continuing the example above, A is the sixth scale degree of C major, so the A minor pentatonic scale would be ( A, C, D, E, G ) :
The minor pentatonic scale replaces the second scale degree with an augmented 4 followed by the fifth and is commonly known as a blues scale.
Jazz improvisers, particularly bassist and guitarist, use these scales in a number of interesting ways. For example, over B♭ Maj7#11, one can use a major pentatonic based on the 2nd scale degree of B♭b (C D E G A) to imply 9, 3, ♯11, 13, and 7 respectively. Similarly, over a fully altered F♯7 chord, one can use the same major pentatonic, this time based on the tritone (C D E G A) to imply ♭5, ♭13, ♭7, ♭9, and ♯9.
Blues scales also come in major and minor varieties.
The A minor blues scale is A C D D♯ E G A ascending or A G E E♭ D C A descending. The difference in the up and down versions is only in its enharmonic spelling, i.e. E♭ vs D♯.
The C major blues scale is C D D♯ E G A C ascending or C A G E E♭ D C descending.
Note well that the C major blues scale and its relative minor, the A minor blues scale, both comprise the same notes. They differ only in which note is nominated as the root.
Guitarists often mix the major and minor pentatonics together along with the blues scale. The dorian and mixolydian modes are similar to this combination and they can also be used in the same context.
Winthrop Sargeant describes the jazz scale as the above scale, defined as, "a definite series of tones within an octave used as the basis of a musical composition," compiled instead from multiple compositions and improvisations (according to Stearns: "a great many jazz records") and is hypothesized as displaying the influence of African music. The E♭ and B♭ are blue notes.
The harmonic minor scale is also of value to many improvisors, as it provides an alternative color for many common chords and chord progressions. An example is C-D-E♭-F-G-A♭-B-C. The C harmonic minor scale can be used on the chords of a piece in C minor, especially on the minor ii V7 i chord progression.
One of the most common uses of the harmonic minor scale is its fifth mode, which is a frequently-heard sound over dominant chords.
The altered dominant scale, also loosely called the altered scale, is so named because all the scale members that can be altered relative to the basic dominant scale (the Mixolydian mode), without losing the dominant quality, are altered. The scale includes both altered ninths (raised and lowered), and both altered fifths (raised and lowered).
The altered fifths coincide enharmonically with the sharp eleventh and the flat thirteenth which would also be considered altered relative to their Mixolydian forms. The tonic, major third (as a diminished fourth), and dominant seventh are retained as essential to the dominant quality.
The scale can also be understood as a mode of the ascending melodic minor scale starting from the 7th scale degree. For a C7 chord, the C♯ melodic minor scale starting from B♯ (C enharmonically) produces the C altered dominant scale enharmonically.
This scale is also called the superlocrian scale, as it is indeed reminiscent of a locrian scale with a flattened 4th, but it is usually regarded as that of major quality.
Another name for this scale is the diminished-wholetone scale because the first tetrachord is that of a (half, whole) diminished scale and the second tetrachord is whole-tone. The bebop scale is used most often.