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A jazz scale is a 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 melodic minor ascending. 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 (Tymoczko 1997). 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 I-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 "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.

Modes of the major scale

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.

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.

Combinations of the characteristic details of these modes are also in common use. For example, the Lydian Dominant uses the raised 4th degree of the Lydian with the flatted seventh of the Mixolydian, yielding C D E F♯ G A B♭ C. Chromatic alterations are also useful, as in the Altered Lydian scale, C D E F♯ G♯ A B C for use on the chord Cmaj7+5.

Bebop scale

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. 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 offbeats (the "+"s) and become passing tones.

There are two commonly used types of Bebop Scales:

Dominant Bebop Scale which adds the raised 7th to Mixolydian: 1 2 3 4 5 6 ♭7 7

Major Bebop Scale which adds ♯5 to Ionian: 1 2 3 4 5 ♯5 6 7

NOTE: A Dominant Bebop Scale works well over an entire ii V. Bebop pianist Barry Harris said "We don't really play ii scales in bebop."

Modes of the melodic minor scale

A great deal of modern jazz harmony arises from the modes of the ascending form of the melodic minor scale. This scale is essentially a diatonic major scale with a flatted third, for example C D E♭ F G A B C (In a melodic minor the sixth and seventh are flattened descending). 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 Melodic Minor:

i: Melodic Minor; i.e., T, 2,♭3, 4, 5, 6, 7 (associated with Cmi maj7 or C-6 chords , functions as a i minor)

II: Phrygian Natural 6; i.e., T,♭2,♭3, 4, 5, 6,♭7 (or Dorian ♭2) (associated with D7 sus ♭9 chord, functions as a dominant)

III: Lydian Augmented; i.e., T, 2, 3,♯4,♯5, 6, 7 (associated with E♭ maj7 +5 chord, functions as a I+)

IV: Lydian Dominant; i.e., T, 2, 3,♯4, 5, 6,♭7 (also known as Mixolydian ♯4) (associated with F7 ♯11 chord, functions as a Dominant not going to I)

V: Mixolydian ♭6 (or simply "fifth mode"); i.e., T, 2, 3, 4, 5,♭6,♭7 (associated with G7 ♭13 chord, functions as a dominant)

vi: Locrian Natural 2; i.e., T, 2,♭3, 4♭5,♭6,♭7 or Aeolian ♭5 (also known as "half-diminished" scale)(associated with Ami7 ♭5, which functions as a ii chord in minor)

VII: Super Locrian (also, "Altered Scale" or "Altered Dominant Scale"); i.e., T,♭2,♯2, 3,♯4 (or ♭5),♭6 (or♯5),♭7 (associated with B7 ♯9 ♭13 chord, functions as a dominant)

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.

Diminished/Octatonic scale

There are two types of diminished scales. Diminished are sometimes called octatonic scales because they utilize 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 diminished scale. For example, the C diminished scale of the half-step-first type, is composed with the same notes as the half-step-first type E♭ diminished scale, and the whole-step-first type D♭ scale:

C diminished: C D♭ E♭ E F♯ G A B♭ C

E♭ diminished: E♭ E F♯ G A B♭ C D♭ E♭

D♭ 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 D♭ E♭ E F♯ G A B♭

In fact, all diminished scales are composed with only three groups of notes. This means you only have to practice these three groups of notes, the full range of your instrument, to practice all the diminished scales!

Whole tone scale

The Whole tone scale, consisting exclusively of whole steps, is often used on V7 +5 chords (G7 + for example).

Pentatonic scales

Two pentatonic scales common to jazz are the major pentatonic scale and the minor pentatonic scale.

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 nomenclature, "minor pentatonic scale," minor is employed in the sense of relative key, as the diatonic A minor scale is the relative minor of the diatonic C major scale.

The minor pentatonic scale replaces the 2nd scale degree with an augmented 4 followed by the fifth and is commonly known as a blues scale

Blues scale

Blues scales also come in major and minor varieties. The C minor blues scale is C E♭ F F♯ G B♭ C ascending or C B♭ G G♭ F E♭ C descending. The differences in the up and down versions are only one of musical spelling, i.e. G♭ vs F♯.

The C major blues scale is C D D♯ E G A C ascending or C A G E E♭ D C descending.

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.

Harmonic minor scale

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 song in C minor, especially on the minor ii V7 i chord progression.

Altered Scale

The melodic minor scale (ascending form) starting from the 7th scale degree. For a c7 chord, the C♯ melodic minor scale starting from B♯ (C enharmonically) Called the Altered Scale because the scale uses 2 altered 5ths and 2 altered 9ths- the same as the Altered (Alt) Chord.

Also called the Superlocrian scale, as it is indeed a locrian scale , but using the melodic minor scale as a basis.

Also called the diminished-wholetone scale because the pattern is that of a diminished scale (H/W) for 4 notes then the scale completes using only whole steps.

Sources

• Tymoczko, Dmitri. “The Consecutive-Semitone Constraint on Scalar Structure: A Link Between Impressionism and Jazz.” Integral 11 (1997): 135–179.